Latent mercaptans as multi-functional additives for halogen-containing polymer compositions

ABSTRACT

Halogen-containing polymer compositions comprising a latent mercaptan-containing heat stabilizer composition substantially free from the offensive odor typically associated with mercaptans are protected during processing by the degradation products of the latent (i.e., blocked) mercaptan which include a free mercaptan. Other products of the degradation are believed to include carbocations of the blocking moiety which are stabilized by a molecular structure in which the electron deficiency is shared by several groups. The latent mercaptan may be the sole heat stabilizer additive but the free mercaptan released during processing may also synergize the activity of metal-based heat stabilizers such as metal salts and organometallic stabilizers such as organotin carboxylates and mercaptides in the polymer composition. The odor of primary mercaptan-containing heat stabilizers in halogenated polymer compositions is masked by a small amount of a latent mercaptan. The latent mercaptans also serve as intermediates in the preparation of anti-oxidants, anti-microbial agents, photostabilizers, and primary heat stabilizers. Highly effective heat stabilizers are prepared by the condensation of formaldehyde and a para-phenol and further condensation of the crude product with a mercapto-containing compound.

FIELD OF THE INVENTION

[0001] This invention relates to stabilizer compositions comprisingdegradation products of a blocked mercaptan present during processing ofthe composition at an elevated temperature, said products including afree mercaptan. This invention also relates to polymer compositionscontaining a polymer normally susceptible to heat-induced deteriorationand the degradation products of a blocked mercaptan present duringprocessing of the composition at an elevated temperature, said productsincluding a free mercaptan. It also relates to such polymer compositionsfurther containing a metallic-based heat stabilizer. This invention alsorelates to articles of manufacture, e.g. pipe, film, and window profile,made from stabilized polymer compositions containing a polymer normallysusceptible to heat-induced deterioration, the degradation products of ablocked mercaptan present during processing of the composition at anelevated temperature, said—based heat stabilizer. Another aspect of thisinvention is the development of a novel reaction scheme which, althoughcrude, affords latent mercaptans which need no purification to be highlyactive PVC heat stabilizers at low use levels.

[0002] This invention also relates to latent mercaptans which aresubstantially free of the offensive odor typical of mercaptans and whichmay be used as anti-oxidants, odorants, anti-microbial agents, chelatingagents and photostabilizers; and a as intermediates for the preparationof anti-oxidants and primary heat stabilizers. It also relates to suchanti-oxidants and primary heat stabilizers.

BACKGROUND OF THE INVENTION

[0003] It is well known that the physical properties of various organicpolymers deteriorate and color changes take place during processing ofthe polymer and during exposure of formed polymer products to certainenvironments. The prime examples of polymers which are susceptible todegradation during processing are the halogen-containing polymers suchas the vinyl and vinylidene polymers in which the halogen is attacheddirectly to carbon atoms. Poly (vinyl chloride) or PVC, copolymers ofvinyl chloride and vinyl acetate, and poly (vinylidene chloride), theprincipal resin in self-clinging transparent food wraps, are the mostfamiliar polymers which require stabilization for their survival duringfabrication into pipes, window casings, siding, bottles, and packagingfilm, etc. When such polymers are processed at elevated temperatures,undesirable color changes often occur within the first 5 to 10 minutesas well as during later stages of the processing. Haziness, whichsometimes accompanies the color changes, is particularly undesirablewhere clear products are needed. The addition of heat stabilizers tosuch polymers has been absolutely essential to the wide-spread utilityof the polymers. From a great deal of work in the development of moreand more effective heat stabilizers there has emerged two principalclasses: organotin compounds and mixed metal combinations.Organotin-based heat stabilizers are the most efficient and widely usedPVC stabilizers. synergistic combinations of alkyltin mercaptides andfree mercaptans are particularly efficient heat stabilizers for PVCduring extrusion. They have not been entirely satisfactory, however,because of several failings on the part of the mercaptan synergist. Manymercaptans give off an offensive odor even at room temperature and theodor grows worse at PVC processing temperatures. The oxidative stabilityof the mercaptans is very often very poor. Oxidation of the freemercaptans diminishes the synergism. Thus, a combination having anenhanced synergism would be welcomed by the PVC industry. Also, becauseof the end-use of articles made from some polymers, many polymericcompositions require the presence of both biocides and heat stabilizersbut the use of the organotin mercaptide/mercaptan combination in such acomposition is often frustrated by the tendency of the free mercaptan todeactivate a biocide such as the much used OBPA (10,10′-oxybisphenoxarsine).

[0004] In U.S. Pat. No. 3,660,331, Ludwig teaches the stabilization ofvinyl halide resins by certain thioethers and thioesters oftetrahydropyran. Better heat stabilizer compositions are still needed,however. The thioethers of this invention satisfy that need.

SUMMARY OF THE INVENTION

[0005] It is an object of this invention, therefore, to provide a heatstabilizer composition having the synergy of a mercaptan plus improvedoxidative stability.

[0006] It is another object of this invention to provide a latentmercaptan-containing heat stabilizer composition which is substantiallyfree from the offensive odor typically associated with mercaptans.

[0007] It is a related object of this invention to provide a latentmercaptan-containing heat stabilizer composition which has a decidedlypleasant odor.

[0008] It is a further object of this invention to provide an improvedpolymeric composition containing a biocide and a latentmercaptan-containing heat stabilizer.

[0009] It is a related object of this invention to provide a polymericcomposition containing a heat stabilizer combination having the synergyof a mercaptan plus improved oxidative stability.

[0010] It is still another object of this invention to provide latentmercaptans as intermediates for the preparation of anti-oxidants,anti-microbial agents, photostabilizers, and primary heat stabilizers.

[0011] These and other objects of the invention which will becomeapparent from the following description are achieved by incorporatinginto a polymeric composition containing a polymer normally susceptibleto heat-induced deterioration a blocked mercaptan which degrades duringprocessing of the composition at an elevated temperature to liberate afree mercaptan. The latent mercaptan may act as the sole heat stabilizerbut the free mercaptan may also synergize the activity of other heatstabilizers in the composition. Other products of the degradation of theblocked mercaptan are believed to include carbocations of the blockingmoiety which are stabilized by a molecular structure in which theelectron deficiency is shared by several groups. Resonance stabilizationand neighboring group stabilization are two of the possible mechanismsby which the carbocations may be stabilized. The carbocations act asintermediates in the formation of stable compounds early in the hotprocessing of halogen-containing polymers. Although such mechanisms andthe resultant carbocations are believed to be an impetus for theliberation of the active free mercaptan, this invention is in no waylimited by the foregoing attempt to explain the working of theinvention. Those skilled in the art will see the resonance stabilizationand neighboring group stabilization that are possible in the followingstructures of the blocked mercaptan; other mechanisms may be at work inother blocked mercaptans represented by these structures that alsoliberate an active free mercaptan upon thermal and/or chemicaldegradation during processing of polymeric compositions containing suchblocked mercaptans. For the purposes of this invention, the terms“blocked mercaptan” and “latent mercaptan” are used interchangeably tomean a thioether which degrades during processing of the composition atan elevated temperature to liberate a free mercaptan.

[0012] The stabilizer compositions of the present invention may comprisea metal-based stabilizer and such a latent mercaptan or mixture oflatent mercaptans.

DETAILED DESCRIPTION OF THE INVENTION

[0013] As used herein: the terms “group” and “radical” are usedinterchangeably, a mono-valent radical has but one valence available forcombining with another radical whereas a di-valent radical may combinewith two other radicals; the term alkyl represents monovalent straightor branched chain hydrocarbon radicals containing, for example, 1 to 20carbon atoms; the term alkylenyl represents divalent, trivalent, andtetravalent straight or branched chain hydrocarbon radicals containing,for example, 1 to 20 carbon atoms; the term aryl represents monovalentC₆-C₁₀ aromatic rings such as benzene and naphthalene; the term alkenylrepresents monovalent straight or branched chain C₂ to C₂₀ hydrocarbonradicals containing at least one double bond; the term aralkylrepresents a monovalent C₁ to C₂₀ hydrocarbon radical having attachedthereto an aryl radical; the term alkaryl represents monovalent arylradicals having attached thereto at least one C₁-C₂₀ alkyl group; theterm cycloalkyl represents monovalent C₃-C₈ saturated cycloaliphaticradicals; the term cycloalkenyl represents C₅-C₈ cycloaliphatic radicalscontaining at least one double bond; the term polyalkoxy means a chainof from 2 to 6 alkoxy groups wherein the alkoxy group is ethoxy,propoxy, isopropoxy, butoxy, or the like, with or without an end groupsuch as hydroxy, acyloxy, benzyloxy, benzoyloxy, butoxy, andtetrahydropyranyloxy; the term halogen-containing organic polymersrepresents halogen-containing vinyl and vinylidene-polymers or resins inwhich the halogen is attached directly to the carbon atoms.

[0014] Also, as used herein: an acyloxyalkyl radical originates from acarboxylic acid ester of an alkyl alcohol; the R¹ radical in Formula 1below, therefore, in the stearic acid ester of mercaptopropanol is thestearoyloxypropyl radical; likewise, the R¹ radical of the oleic acidester of mercaptopropanol, which is one the tallate esters of thatalcohol, is the oleoyloxypropyl radical; the R¹ radical oflauryl-3-mercaptopropionate, on the other hand, isdodecyloxy-carbonylpropyl.

[0015] The polymeric compositions of this invention contain polymersnormally susceptible to heat-induced deterioration through autoxidationsuch as the above-noted halogen-containing polymers. The stabilizercompositions of this invention are particularly suited to impart asuperior stabilization against the deteriorative effects of heat andultra-violet light on halogen-containing organic polymers compared tothat imparted by stabilizer compositions previously known in the art.

[0016] The halogen-containing organic polymers which can be stabilizedaccording to this invention include chlorinated polyethylene having 14to 75%, e.g. 27%, chlorine by weight, chlorinated natural and syntheticrubber, rubber hydrochloride, chlorinated polystyrene, chlorinatedpolyvinyl chloride, polyvinyl bromide, polyvinyl fluoride, copolymers ofvinyl chloride with 1 to 90%, preferably 1 to 30%, of a copolymerizableethylenically unsaturated material such as, for example, vinyl acetate,vinyl butyrate, vinyl benzoate, vinylidene chloride, diethyl fumarate,diethyl maleate, other alkyl fumarates and maleates, vinyl propionate,methyl acrylate, 2-ethylhexyl acrylate, butyl acrylate and other alkylacrylates, methyl methacrylate, ethyl methacrylate, butyl methacrylateand other alkyl methacrylates, methyl alpha-chloroacrylate, styrene,trichloroethylene, vinyl ethers such as vinyl ethyl ether, vinylchloroethyl ether and vinyl phenyl ether, vinyl ketones such as vinylmethyl ketone and vinyl phenyl ketone, 1-fluoro-2-chloroethylene,acrylonitrile, chloroacrylonitrile, allylidene diacetate andchloroallylidene diacetate. Typical copolymers include vinylchloride-vinyl acetate (96:4 sold commercially as VYNW), vinylchloride-vinyl acetate (87:13), vinyl chloride-vinyl acetate-maleicanhydride ((86:13:1), vinyl chloride-vinylidene chloride (95:5); vinylchloride-diethyl fumarate (95:5), and vinyl chloride 2-ethylhexylacrylate (80:20). In addition to the stabilizer compositions of thisinvention, there can also be incorporated into the halogen-containingorganic polymer conventional additives such as plasticizers, pigments,fillers, dyes, ultraviolet light absorbing agents, densifying agents,biocides and the like.

[0017] Preferably, the halogen-containing organic polymer is a vinylhalide polymer, more particularly a vinyl chloride polymer. Usually, thevinyl chloride polymer is made from monomers consisting of vinylchloride alone or a mixture of monomers comprising, preferably, at leastabout 70% by weight based on the total monomer weight of vinyl chloride.

[0018] FORMULA 1 is representative of the blocked mercaptans that aresuitable for the purposes of this invention:

[0019] wherein a is 0 or 1, m and n are 0 or 1; y=1 to 4; when y=1, z is1 to 4; and when y is more than 1, z is 1; R1 is an alkyl, alkylenyl,cycloalkyl, cycloalkylenyl, aryl, alkaryl, aralkyl, aralkylenyl,hydroxyalkyl, dihydroxyalkyl, hydroxy(polyalkoxy)alkyl, alkoxyalkyl,hydroxyalkoxyalkyl, alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl),alkoxy(polyalkoxy)alkyl, alkoxy(polyalkoxy)carbonylalkyl, carboxyalkyl,acyloxyalkyl, acyloxy(hydroxyalkyl), acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxy)carbonylalkyl, mercaptoalkyl, mercaptoalkylenyl,mercaptoalkoxycarbonylalkyl, mercaptoalkoxycarbonylalkylenyl,alkoxycarbonyl(amido)alkyl, alkyl carbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, R⁶, and R⁷ are independently hydrogen, ahydroxyl, mercapto, acyl, alkyl, alkylenyl, aryl, haloaryl, alkaryl,aralkyl, hydroxyalkyl, mercaptoalkyl, hydroxyaryl, alkoxyaryl,alkoxyhydroxyaryl, mercaptoaryl groups having from 1 to 22 carbon atoms;X is aryl, haloaryl, alkaryl, hydroxyaryl, dihydroxyaryl, alkoxyaryl,arylcycloalkyl, or a heteroatom, with the option that when a is 1 and mis 1, R⁶ and R⁷ form a heterocyclic moiety in conjunction with X asnitrogen, and with the further option that when a=1 and m=0, one of R¹,R³, and R⁵ joins with R⁷ and X to form a heterocyclic moiety with X as aheteroatom selected from the group consisting of oxygen and sulfur; withthe proviso that z is 1 or 2 when X is aralkaryl, R⁶ and R⁷ arehydroxyl, a is 1 and m is 1, and with the further proviso that whenR⁶≠hydroxyl or mercapto, z is 1.

[0020] A polymeric composition wherein the blocked mercaptan has thefollowing structure is another embodiment of this invention:

[0021] wherein a is 0 or 1, m and n are 0 or 1; y=1 to 4, when y=1, z is1 to 4 when y is more than 1 z is 1; R1 is an an alkyl, alkylenyl,cycloalkyl, cycloalkylenyl, aryl, alkaryl, aralkyl, aralkylenyl,hydroxyalkyl, dihydroxyalkyl, hydroxy(polyalkoxy)alkyl,alkoxy(polyalkoxy)carbonylalkyl, alkoxyalkyl, hydroxyalkoxyalkyl,alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl), alkoxy(polyalkoxy) alkyl,carboxyalkyl, acyloxyalkyl, acyloxy(hydroxyalkyl), acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxy)carbonylalkyl, mercaptoalkyl, mercaptoalkylenyl,mercaptoalkoxycarbonylalkyl, mercaptoalkoxycarbonylalkylenyl,alkoxycarbonyl(amido)alkyl, alkylcarbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, R⁶, and R⁷ are independently hydrogen, ahydroxyl, mercapto, alkyl, alkylenyl, aryl, haloaryl, alkaryl, aralkyl,hydroxyalkyl, mercaptoalkyl, hydroxyalkylmercaptoalkyl,mercaptoalkylenyl, hydroxyaryl, alkoxyaryl, alkoxyhydroxyaryl,arylcarbonyl, or mercaptoaryl radical having from 1 to 22 carbon atoms;when a=1, X is aryl-ycloalkyl or a heteroatom, and when a=0, X is aryl,haloaryl, alkaryl, alkoxyaryl, arylcycloalkyl, or a heteroatom, with theoption that when a is 1 and m is 0, one of R3 and R⁵ joins with R⁷ and Xto form a heterocyclic moiety with X as a heteroatom selected from thegroup consisting of oxygen and sulfur, and with the further option thatwhen a is 1 and m is 1, R⁶ and R⁷ form a heterocyclic moiety inconjunction with X as a nitrogen atom.

[0022] The mercaptan-containing organic compounds which may be convertedinto latent mercaptans for the purposes of this invention are well-knowncompounds and include alkyl mercaptans, mercapto esters, mercaptoalcohols, and mercapto acids. See, for example, U.S. Pat. Nos. 3,503,924and 3,507,827. Alkyl mercaptans having from 1 to about 200 carbon atomsand from 1 to 4 mercapto groups are suitable. Mercaptan-containingorganic compounds which include R¹ have structures illustrated by thefollowing formulas:

[0023] wherein R¹⁰ and R¹⁹ are the same or different and are

[0024] —OH, —SH, aryl, C₁ to C₁₈ alkyl, or —H;

[0025] R¹¹ is —H, aryl, or C₁ to C₁₈ alkyl;

[0026] R¹² is cycloalkyl, cycloalkenyl or phenyl;

[0027] R¹³ is

[0028] —SH, aryl, C₁ to C₁₈ alkyl, —OH or —H

[0029] with the proviso that in formula (MC2) when R¹² is phenyl, R¹³ is—OH and i=0, then the —SH groups are on non-adjacent carbon atoms;

[0030] R¹⁴ is —H or a divalent group which may contain halogen, hydroxy,mercapto or alkyl substituents and which when R¹² is phenyl combineswith the phenyl to form a naphthalene ring;

[0031] R¹⁵ is

[0032] R¹⁷ is —H or alkyl, alkenyl, aryl, aralkyl, alkaryl, cycloalkyl,cycloalkylenyl;

[0033] R¹⁸ is arylene, C₁ to C₈ alkylenyl,

[0034] or —(CH₂—CH₂ —O)_(b)—CH₂—CH₂—

[0035] wherein b is an integer from 1 to 6;

[0036] i=0 or an integer from 1 to 6 inclusive;

[0037] j=0, 1, 2 or 3; and

[0038] f=1 or 2.

[0039] Mercaptan-containing organic compounds preferred as intermediatesin the preparation of the latent mercaptans of this invention are thosecompounds according to formula (MCl) where R¹¹ is —H, R¹⁹ is —H, R¹⁰ isOH or

[0040] and i=1; those compounds according to formula (MC2) where R¹² isphenyl, R¹¹ is —H, R¹³ is —H, R¹⁴ is —H, i=1, and j=1; those compoundsaccording to formula (MC3) where R¹¹ is —H, R¹⁵ is

[0041] and i=1; those compounds according to formula (MC4) where R¹¹ is—H and i=1; those compounds according to formula (MC5) where R¹⁶ is—C₂H₅ or

[0042] R¹¹ is —H and i=1; and those compounds according to formula (MC6)where R¹¹ is —H and i=1.

[0043] Examples of the mercaptan-containing organic compounds describedby formula (MC1) include, but are not limited to, the followingcompounds:

[0044] Examples of the mercaptan-containing organic compounds describedby formula (MC2) include, but are not limited to, the followingcompounds:

[0045] Examples of mercaptan-containing organic compounds represented byformula (MC3) include, but are not limited to the following compounds:

[0046] The mercaptan-containing organic compounds described by formula(MC4) are exemplified by, but are not limited to, the following:

[0047] The mercaptan-containing organic compounds represented by formula(MC₅) are exemplified by, but are not limited to, the following:

[0048] The mercaptan-containing organic compounds represented by formula(MC6) are exemplified by, but are not limited to, the following:

[0049] One of the advantages of this invention is that the offensiveodor of the mercaptans is masked by the blocking group so that thelatent mercaptan thus created may be put into a PVC composition or thelike with little or no offense to the operator with the knowl-edge thatthe free mercaptan will be released as a degradation product when thetreated composition is heated during the usual processing, e.g.extrusion. This advantage is also useful for the liquid polysulfideshaving a molecular weight of from about 1000 to about 8000 sold underthe LP trademark by Morton International, Inc.

[0050] The blocking compounds are preferably those which are capable offurnishing a stabilized carbocation having a molecular structure inwhich the electron deficiency is shared by several groups. Resonancestabilization and neighboring group stabilization are two of thepossible mechanisms by which the carbocations may be stabilized.Polarized, unsaturated compounds exemplified by 3,4-dihydropyran,2-methoxy-3,4-dihydropyran, styrene, α-methylstyrene, vinyl benzylchloride, indene, 2-vinylpyridine, N-vinylpyrrolidone, vinyl acetate,octadecyl vinyl ether, cyclohexyl divinyl ether, ethyleneglycolmonovinyl ether, allyl phenyl ether, trans-cinnamaldehyde,N-methyl-N-vinylacetamide, N-vinylcaprolactam, isoeugenol, and2-propenylphenol are suitable. Compounds having labile halogen atomswhich split off as hydrogen chloride in a condensation reaction with themercaptan, as exemplified by triphenylmethyl chloride, benzyl chloride,and bis(chloromethyl)benzene, are also suitable. The mercaptan may alsobe blocked by condensation with an aldehyde such as butyraldehyde orwith a benzyl alcohol such as benzene dimethanol. A preferred blockingagent is 2-hydroxybenzyl alcohol, a well known intermediate in theperfume, agricultural, and plastics industries.

[0051] In general, the procedure for adding the mercapto group of a freemercaptan across the double bonds of polarized, unsaturated compoundsis:

[0052] To a stirred mixture of the mercaptan, acid catalyst, andoptionally, a small percentage of antioxidant to irhibit radicalreactions, under nitrogen atmosphere is added dropwise the polarized,unsaturated compound, either neat or in solution, while maintaining thetemperature between 10°-70° C. The mixture or solution is then heatedfor between 1 to 6 hours at 35°-70° C. and conversion to product ismonitored by gas chromatography and iodine titration for SH. The acidcatalyst is removed by an alkaline wash and the resulting product isdried with magnesium sulfate and filtered. The solvent, if required, isremoved under reduced pressure at <50° C. to yield the latent mercaptan.This generalized procedure is referred to hereinafter as Procedure A.

[0053] In accordance with Procedure A, for example, mercaptoethanol isadded across the double bond of N-vinylcaprolactam to yieldN-2-hydroxyethylthioethylcaprolactam. Mercaptoethyldecanoate (ormercaptoethylcaproate) reacts with 3,4-dihydropyran in that procedure togive 2-S-(tetrahydropyranyl)thioethyldecanoate.Bis(hydroxyethylthioethyl) cyclohexyl ether is made from themercaptoethanol and cyclohexyl di-vinyl ether. In like manner, thecorresponding caprate, oleate, and tallate esters form the correspondingcyclohexyl ethers. Also, indene is converted by the addition of themercaptoethanol to 2H-dihydroindenylthio-ethanol.

[0054] A generalized procedure for the condensation of a free mercaptanwith a labile halogen-containing compound is as follows:

[0055] To a stirred mixture of the mercaptan and halogen-containingcompound under nitrogen atmosphere is added dropwise a solution ofsodium methoxide in methanol while maintaining the temperature below 50°C. Optionally, the reaction is allowed to proceed without the additionof a base source and the liberated hydrogen chloride is removed bynitrogen gas sweep and neutralized with the use of an external acidscrubber. The mixture or solution is then heated for between 2 to 24hours at 50°-70° C. and conversion to product is monitored by gaschromatography and iodine titration for % SH. The product is thenneutralized, washed with water, dried with magnesium sulfate, andfiltered. The solvent, if required, is removed under reduced pressure at<50° C. to yield the latent mercaptan. This generalized procedure isreferred to hereinafter as Procedure B.

[0056] A generalized procedure for the condensation of a free mercaptanwith a labile hydroxyl-containing compound is as follows:

[0057] To a stirred solution of the mercaptan, acid catalyst, andsolvent under nitrogen atmosphere is added the hydroxy-containingcompound either neat or in solution while maintaining the temperature<45° C. The solution is then heated to 45°-75° C. for between 1 to 10hours and conversion to product is monitored by gas chromatography andiodine titration for % SH. Optionally, an azeotropic solvent is chosenfor removal of reaction water by an appropriate means at refluxtemperatures, typically 60°-120° C. Completion of reaction is achievedafter the theory amount of water has been collected. The acid catalystis removed by alkaline wash and the resulting solution is dried withmagnesium sulfate and filtered. The solvent is removed under reducedpressure at <55° C. to yield the latent mercaptan. This procedure isreferred to hereinafter as Procedure C.

[0058] For example, 2-hydroxybenzyl alcohol condenses withmercaptoethanol in accordance with Procedure C to form1-(2-hydroxyphenyl)-1-S-(2-hydroxyethylthio)methane.

[0059] A generalized procedure for the reaction of a free mercaptan witha glycidyl ether is as follows:

[0060] To a stirred mixture of the mercaptan and acid catalyst undernitrogen atmosphere is added the glycidyl ether, either neat or insolution, while maintaining the temperature between 25°-60° C. Themixture or solution is then heated to between 50°-75° C. for a period of1 to 6 hours and conversion to product is monitored by gaschromatography and iodine titration for % SH. The acid catalyst isremoved by alkaline wash, the resulting product is dried with magnesiumsulfate, and filtered. The solvent, if required, is removed underreduced pressure at <55° C. to yield the latent mercaptan. For example,the reaction between mercaptoethanol and glycidyl neodecanoate givesC₉H₁₉C(═O)OCH₂CH(OH)CH₂SCH₂CH₂OH. This procedure is referred tohereinafter as Procedure D.

[0061] A generalized procedure for the condensation of a free mercaptanwith an aldehyde is as follows:

[0062] To a stirred solution of the mercaptan, acid catalyst, andazeotropic solvent under nitrogen atmosphere is added the aldehyde withheating to reflux, typically between 65°-120° C., for removal ofreaction water. Completion of reaction is achieved after the theoryamount of water has been collected. Optionally, to a stirred solution ofmercaptan, aldehyde, and ether is added BF₃-etherate dropwise underreflux conditions. The solution is refluxed for between 1 to 6 hours andconversion to product is monitored by gas chromatography. The acidcatalyst is removed by alkaline wash, the solution is dried withmagnesium sulfate and filtered. The solvent is removed under reducedpressure at <65° C. to yield the latent mercaptan. This generalizedprocedure is referred to hereinafter as Procedure E.

[0063] Examples of the blocked mercaptans of this invention includecompounds having the following formulas, as each relates to FORMULA 1:

[0064] Formula

[0065] a=1, m=1, n=0; y=1, z is 1; X is nitrogen, R⁶ and R⁷ are joinedto form —CH₂—CH₂—CH₂—C═(O)—; R⁴ is hydrogen; R⁵ is methyl; and R¹ ishydroxyethyl.

[0066] a=1, m=1, n=0; y=1, z is 1; X is nitrogen, R⁶ is acetyl, R⁷ ismethyl, R⁵ is methyl, R⁴ is hydrogen, and R¹ is hydroxyethyl.

[0067] a=1, m=0, n=0; y=1, z is 1; X is oxygen, R⁵ and R⁷ are joined toform —CH₂—CH₂—CH₂—CH₂—; R⁴ is hydrogen, and R¹ is hydroxyethyl.

[0068] a=1, m=0, n=1, y=1, z=1; X is oxygen, R³ and R⁷ join to form—CH₂—CH₂—CH₂—; R², R⁴ and R⁵ are hydrogen, and R¹ is hydroxyethyl.

[0069] a=1, m=0, n=0, y=1, z=1; X is oxygen, R⁵ and R⁷ join to form—CH₂—CH₂—CH₂—CH₂—; R⁴ is hydrogen, and R¹ is 2-ethoxytetrahydropyranyl.

[0070] a=1, m=0, n=0, y=1, z=1; X is oxygen, R⁵ and R⁷ join to form—CH₂—CH₂—CH₂—CH₂—; R⁴ is hydrogen, and R¹ is 3-ethoxytetrahydropyranyl.

[0071] a=1, m=0, n=1, y=1, z=1; X is oxygen, R³ and R⁷ join to form—CH₂—CH₂—CH₂—; R², R⁴ and R⁵ are hydrogen, and R¹ is2-ethoxytetrahydropyranyl.

[0072] a=1, m=0, n=1, y=1, z=1; X is oxygen, R³ and R⁷ join to form—CH₂—CH₂—CH₂—; R², R⁴ and R⁵ are hydrogen, and R¹ is3-ethoxytetrahydropyranyl.

[0073] a=0, m=0, n=0, y=1, z=1; X is phenyl, R⁴ is methyl, R⁵ ishydrogen, and R¹ is hydroxyethyl.

[0074] a=0, m=0, n=1, y=1, z=1, X is phenyl, R², R³, R⁴, and R⁵ arehydrogen, and R¹ is hydroxyethyl.

[0075] a=0, m=0, n=0, z=1; y=1, X is phenyl, R⁴ and R⁵ are hydrogen, andR¹ is hydroxyethyl.

[0076] a=1, m=0, n=0, y=1, z=1; X is phenyl, R⁴ and R⁵ are hydrogen, R⁷is o-hydroxy, and R¹ is hydroxyethyl.

[0077] a=0, m=0, n=0, y=1, z=1; X is phenyl, R⁴ and R⁵ are hydrogen, andR¹ is mercaptoethoxycarbonylmethyl.

[0078] a1, m=0, n=1, y=1, z=1; X is oxygen, R², R⁴ and R⁵ are hydrogen,R³ is methyl, R⁷ is phenyl, and R¹ is hydroxyethyl.

[0079] a=1, m=0, n=0, y=1, z=1; X is oxygen, R⁷ and R¹ are joined toform an ethylenyl radical, R⁴ is hydrogen, and R⁵ is propyl.

[0080] a=0, m=1, n=1, y=1, z=1; X is oxygen, R², R³, R⁶ and R⁴ arehydrogen, R⁵ is 2-methyleneoxytolyi, and R¹ is hydroxyethyl.

[0081] a=1, m=0, n=1, y=1, z=1; X is oxygen, R², R³, R⁴ and R⁷ arehydrogen, R⁵ is butoxymethyl, and R¹ is hydroxyethyl.

[0082] a=1, m=0, n=0, y=1, z=1; X is phenyl, R⁴ is hydrogen, R⁵ isethyl, R⁷ is o-hydroxy, and R¹ is hydroxyethyl.

[0083] a=1, m=0, n=1, y=1, z=1; X is phenyl, R³, R⁴ and R⁵ are hydrogen,R² is methyl, R⁷ is o-hydroxy, and R¹ is hydroxyethyl.

[0084] a=1, m=0, n=0, y=1, z=2; X is phenyl, R⁴ is hydrogen, R⁵ isethyl, R⁷ is o-hydroxy, and R¹ is hydroxyethyl.

[0085] a=1, m=0, n=0, y=1, z=1; X is m-methoxyphenyl, R⁴ is hydrogen, R⁵is ethyl, R⁷ is p-hydroxy, and R¹ is hydroxyethyl.

[0086] a=0, m=0, n=0, y=1, z=2; X is tetrachlorophenyl, R⁴ and R⁵ arehydrogen, and R¹ is hydroxyethyl.

[0087] a=1, m=0, n=0, y=1, z=1; X is o, p-dihydroxyphenyl, R⁷ ism-phenylcarbonyl, R⁴ is hydrogen, R⁵ is —CH₂CH₃, and R¹ is hydroxyethyl.

[0088] a=1, m=0, n=0; y=1, z is 1; X is oxygen, R⁵ and R⁷ are joined toform —CH₂—CH₂—CH₂—CH₂—; R⁴ is hydrogen, and R¹ is decanoyloxyethyl.

[0089] a=1, m=0, n=0; y=1, z is 1; X is p-hydroxyphenyl, R⁴ and R⁵ arehydrogen, R⁷ is m-methoxy, and R¹ is hydroxyethyl.

[0090] As stated above, the. stabilizer compositions of the presentinvention comprise a latent mercaptan as the sole heat stabilizer or ina system comprising a metal-based stabilizer, an organic-basedstabilizer, or a hydrotalcite-based stabilizer in admixture with thelatent mercaptan. Metal-based stabilizers are defined for the purposesof this invention as metal salt stabilizers and organometallicstabilizers. The metal salt stabilizers are exemplified by barium,strontium, calcium, cadmium, zinc, lead, tin, magnesium, cobalt, nickel,titanium, antimony, and aluminum salts of phenols, aromatic carboxylicacids, fatty acids, epoxidized fatty acids, oxalic acid, carbonic acid,sulfuric acid, and phosphoric acid. Calcium stearate, calcium2-ethyl-hexeate, calcium octoate, calcium oleate, calcium ricin-oleate,calcium myristate, calcium palmitate, calcium laurate, barium laurate,barium stearate, barium di(nonylphenolate), magnesium stearate, zincstearate, zinc octoate, cadmium laurate, cadmium octoate, cadmiumstearate, sodium stearate and other Group I and II metal soaps areexamples of suitable salts. Other metal salts such as lead stearate,hydrotalcite, aluminum stearate, etc, can be used. Metal saltstabilizers may constitute from about 0.1 to about 10%, preferably0.1-5% by weight of the halogen containing resin.

[0091] Conventional organometallic stabilizers include the organotincarboxylates and mercaptides. Such materials include butyltin trisdodecyl mercaptide, dibutyltin dilaurate, dibutyltin didodecylmercaptide, dianhydride tris dibutylstannane diol, dihydrocarbontinsalts of carboxy mercaptals such as those set forth in Hechenbleikner etal.(U.S. Pat. No. 3,078,290). There can be included any of the vinylchloride resin stabilizers set forth in Salyer (U.S. Pat. No.2,985,617).

[0092] As an example of a system involving an organic-based stabilizer,a combination of a latent mercaptan and an N-substituted maleimide hasbeen found to be synergistic in the stabilization of a flexible PVCformulation.

[0093] The stabilizer compositions of this invention comprise from about10% to about 100%, preferably from about 35% to about 85%, by weight ofone or more latent mercaptans, based on the total weight of thestabilizer composition, the balance comprising the metal-based,organic-based, or hydrotalcite-based stabilizer. Preferably, thestabilizer compositions of this invention comprise a mono-organotincompound or mixture of mono-organotin compounds, and, optionally, adiorganotin compound or mixture of diorganotin compounds or mixtures ofmono-organotin and di-organotin compounds. Thus, when no diorganotincompound or mixture of diorganotin compounds is employed in thepreferred stabilizer of this invention, the mono-organotin compoundswill comprise from about 10% to about 90% by weight, preferably about15% to about 65% by weight of the total weight of the stabilizercomposition. When it is desirable to utilize a diorganotin compound ormixture of diorganotin compounds in the practice of this invention, saiddiorganotin compound or mixture of diorganotin compounds may comprisefrom about 0.05% to about 75%, by weight, preferably from about 0.05% toabout 35% by weight of the total weight of the stabilizer composition.

[0094] The mono-organotin compounds useful in the compositions of thisinvention contain one or more tetravalent tin atoms each of which haveone direct tin to carbon bond and have structures selected from thefollowing formulas:

[0095] wherein Z and Z′ are the same or different and are selected from

[0096] —SR³², O—R³³, and

[0097] with the proviso that in formula (E) when z=1 and in formulas (C)and (D) at least one Z or Z″ is —SR³²;

[0098] Y is

[0099] W and W¹ are the same or different and are oxygen or sulfur; R³⁰and R³¹ are the same or different and are selected from alkyl, aryl,alkenyl, aralkyl, alkaryl, cycloalkyl, cycloalkenyl,

[0100] R³² is alkyl, alkenyl, aryl, aralkyl, cycloalkyl, cycloalkenyl,

[0101] —R³⁴—S—R⁴², or —R³⁴—O—R³³;

[0102] R³³ is alkyl, alkenyl, aryl, aralkyl, alkaryl, cycloalkyl, orcycloalkenyl;

[0103] R³⁴ is alkylene of at least 2 carbon atoms, arylene, alkenyleneof at least 2 carbon atoms, cycloalkylene, or cycloalkenylene;

[0104] R³⁵ is alkylene, arylene, alkenylene of at least 2 carbon atoms,cycloalkylene, or cycloalkenylene;

[0105] R³⁶ is R³⁴;

[0106] R³⁷ is nothing or R³⁵;

[0107] R³⁸ is C₁ to C₄ alkylenyl;

[0108] R³⁹ is —H or a monovalent C₁ to C₂₀ hydrocarbon radical;

[0109] R⁴⁰ and R⁴¹ are the same or different and are each C₁ to C₂₂alkyl or C₁ to C₂₀ alkoxy;

[0110] R⁴² is —H or R³³;

[0111] q=0 or an integer from 1 to 4 inclusive;

[0112] v=an integer from 1 to 8 inclusive; and

[0113] w=0, 1 or 2, x=0 or 1, z=0 or 1 with the proviso that when

[0114] x=0 then z=1, when x=1 then z=0 and w=1, when w2 then x=0 andz=1, and when w=0 then x=0, z=1 and Y is —W—R³⁴—W¹— or

[0115] The preferred mono-organotin compounds useful in this inventionare those compounds according to formula (A) where R³⁰ is methyl, butylor octyl and W is sulfur; those compounds according to formula (B) whereR³¹ is methyl or butyl, W is sulfur, Z is —SR³² where R³² is

[0116] those compounds according to formula (C) where R³⁰ is methyl orbutyl, Z is —SR³² where R³² is

[0117] those compounds according to formula (D) where R³⁰ is methyl, Zis —SR³² where R³² is

[0118] R³¹ is methyl, Z′ is —SR³² where R³² is

[0119] Y is —S—, and q=0; and those compounds according to formula (E)where R³⁰ is methyl, Z is —SR³² where R³² is

[0120] R³¹ is methyl, Z′ is —SR³² where R³² is

[0121] Y is —S—, W=1, x=0, and z=1.

[0122] Examples of mono-organotin compounds which are useful in thisinvention include, but are not limited to, those illustrated in Tables1-4 below. Thus, representative of the mono-organotin compoundsdescribed by formulas (A) and (B) are those illustrated in Table 1below. TABLE 1 (A)

(B)

Mono- organotin Com- pound No. R³⁰ R³¹ W Z 1 —C₄H₉ — S — 2 —C₈H₁₇ — O —3 — —CH₃ S

4 — —CH₃ S

5 —

S

[0123] Examples of mono-organotin compounds represented by formula (C)are illustrated in Table 2 below. TABLE 2 (C) R³⁰-Sn-Z₃ Mono-organotinCompound No. R³⁰ Z 6 —CH₃

7 —C₄H₉

[0124] The mono-organotin compounds illustrated in Table 3 below arerepresentative of compounds described in formula (D). TABLE 3 (D)

Mono-organotin Compound No. R³⁰ and R³¹ Z Z¹ Y q 8 —CH₃

Same as Z —S— 0 9

Same as Z —S—S— 0 10 —CH₃

Same as Z

1 11 —CH₃

Same as Z —S— 0 12 —C₄H₉

Same as Z

0 13 —CH₃

Same as Z —S— 0 14 —C₄H₉

Same as Z

0

[0125] The mono-organotin compound illustrated in Table 4 below isrepresentative of compounds described by formula (E). TABLE 4 (E)

Mono- organotin Compound R³⁰ and No. R³¹ Z and Z¹ Y w x z 15 —CH₃

—S— 1 0 1

[0126] As used in Tables 1-3 above, and throughout this specification,the radicals —C₄H₉, —C₈H₁₇, —C₁₂H₂₅, —C₉H₁₉ and —C₁₀H₂₁ representn-butyl, n-octyl, n-dodecyl, n-nonyl and n-decyl respectively.

[0127] The carboxyl radicals

[0128] are derived from oleic acid, scearic acid, n-octanoic acid,lauric acid, and pelargonic acid respectively. Likewise, the radicals—C₁₃H₂₇, —OC₁₈H₃₇, and —OC₈H₁₇, are derived from tridecanol, stearylalcohol and iso-octanol, respectively.

[0129] The diorganotin compounds useful in the practice of thisinvention contain one or more tetravalent tin atoms, at least one ofwhich has direct bonds to two carbon atoms and have structure selectedfrom the following formulas:

[0130] wherein R³⁰, R³¹, W, Z, Z¹, Y, w and z are as previously defined;

[0131] n=0, 1 or 2, p=0, 1 or 2 with proviso that n+p=2, and m=1 to 5;

[0132] y=1 or 2, y=2 with the proviso that when w=0 then Y is—W—R³⁴—W¹—, or

[0133] and in formula (J) when z=1 and in formulas (G) and (H) at leastone Z or Z¹ is —SR³².

[0134] The preferred diorganotin compounds used in the practice of thisinvention are those compounds according to formula (F) where R is methylor butyl, R³¹ is methyl or butyl and W is sulfur; those compoundsaccording to formula (G) where R is methyl or butyl, R³¹ is methyl orbutyl, Z is —SR³² where R³² is

[0135] those compounds according to formula (H) where R³⁰ is methyl orbutyl, R³¹ is methyl or butyl, Y is —S—, Z is —SR³² where R³² is

[0136] m=1, n=2 and p=0; and those compounds according to formula (J)where R³⁰ is methyl or butyl, R³¹ is methyl or butyl, Z is —SR³² and R³²is

[0137] Y is —S—, w=1, y=1 and z=1.

[0138] Examples of diorganotin compounds according to formula (F)include, but are not limited to, the compounds illustrated in Table 5below. TABLE 5 (F)

Diorganotin Compound No. R³⁰ R³¹ W 1 —C₄H₉ —C₄H₉ S 2 —C₈H₁₇ —C₈H₁₇ O

[0139] Examples of diorganotin compounds according to formula G include,but are not limited to, the compounds in Table 6 below. TABLE 6 (G)

Diorganotin Compound No. R³⁰ R³¹ Z and Z¹ C

Same as R³⁰

D —CH₃ Same as R³⁰

[0140] Examples of diorganotin compounds according to formula (H)include, but are not limited to, the compounds in Table 7 below. TABLE 7(H)

Diorganotin Compound No. R³⁰ and R³¹ Z Z¹ Y n p m E —CH₃

Same as R³⁰ —S— 1 1 1 F —C₄H₉

Same as R³⁰ —S— 1 1 1

[0141] Examples of diorganotin compunds according to formula (J)include, but are not limited to, the compounds in Table 8 below. TABLE 8(J)

Diorganotin Compound No. R³⁰ R³¹ Z Y w y z G —C₄H₉ —C₄H₉

—S— 1 1 1

[0142] The mono-organotin compounds and diorganotin compounds useful inthe compositions of this invention may be prepared by methods well-knownin the art such as the reaction of a mono- or dialkyltin chloride with amercaptoalkyl carboxylate or an alkyl thioglycolate in the presence of abase to scavenge hydrogen chloride. Methyltin trichloride, dimethyltindichloride, butyltin trichloride, dibutyltin dichloride, ethylhexyltintrichloride, and dioctyltin dichloride are examples of organotin halidesthat are suitable for the preparation of useful stabilizers for thisinvention. See for example, U.S. Pat. Nos. 3,565,930, 3,869,487,3,979,359, 4,118,371, 4,134,878 and 4,183,846 all of which areincorporated herein by reference.

[0143] Monosulfides and/or polysulfides of the mercaptoalkylcarboxylates and alkyl thioglycolates are also suitable as metal basedstabilizers in the compositions of this invention for improving theresistance of halogen-containing polymers to deterioration when heatedto 350° F. (177° C.) during processing. Polysulfides are mixtures ofcompounds having from 2 to 10 or more sulfur atoms linked together butcompounds having from 2 to 4 sulfur atoms are preferred along with themonosulfides. Said sulfides are made by heating stoichiometricquantities of a mercaptoalkyl ester or alkylthiocarboxylate and anorganotin chloride in water and ammonium hydroxide to about 30° C. (86°F.), slowly adding an alkali metal mono- or polysulfide, and heating thereaction mixture further to about 45° C. before separating the productfrom said mixture. The sulfides may be described as a blend of thereaction products which are believed to include the monosulfides andpolysulfides of the mercaptoalkylesters and thioglycolates. Saidsulfides contain from about 10 to about 42 % by weight of tin and fromabout 8 to about 42% by weight of sulfur. The sulfides of themercaptoalkyl esters and their preparation are described in U.S. Pat.No. 4,062,881. These sulfides are believed to include the bis[(monoorganotin) bis(mercapto-alkylcarboxylate)] monosulfides andpolysulfides, and bis((diorganotin)mono(mercaptoalkyl-carboxylate)]monosulfides and polysulfides, and products which arise duringequilibrium reactions among said mono- and polysulfides. The chemicaland patent literature contain numerous examples demonstrating thatmembers of different classes of organotin compounds may react with oneanother under certain conditions to yield products containing one ormore tin atoms wherein at least a portion of the tin atoms are bonded todifferent combinations of radicals than they were before being mixedtogether.

[0144] Conventional non-metallic stabilizers and antioxidants can alsobe included in the stabilizer compositions of the present invention toassist in improving the properties of the halogen containing resin.Thus, there can be included 0.01-10%, preferably 0.1-5% based on theresin of sulfur containing compounds such as dilauryl-thiodipropionate,distearyl 3,3′-thiodipropionate, dicyclohexyl-3,3-thiodipropionate,dioleyl-3,3′-thiodipropionate, dibenzyl-3,3′-thiodipropionate,didecyl-3,3′-thiodipropionate, dibenzyl-3,3′-thiodipropionate,diethyl-3,3′-thiopropionate, lauryl ester of 3-methylmercaptopropionicacid, lauryl ester of 3-butylmercaptopropionic acid, lauryl ester of3-lauryl mercaptopropionic acid, and phenyl ester of 3-octylmercaptopropionic acid.

[0145] Phenolic antioxidants can also be added in an amount of 0.01-10%,preferably 0.1-5% of the halogen-containing resin. Examples of suchantioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole,propyl gallate, 4,4′-thiobis(6-t-butyl-m-cresol),4,4′-cyclohexylidenediphenol, 2, 5-di-t-amyl hydroquinone,4,4,′-butylidene bis(6-t-butyl-m-cresol), hydroquinone monobenzyl ether,2,2′-methylene-bis(4-methyl-6-t-butyl phenol), 2,6-butyl-4-decyloxyphenol, 2-t-butyl-4-dodecyloxy phenol, 2-t-butyl-4-dodecyloxy phenol,2-t-butyl-4-octadecyloxy phenol, 4,4′-methylene-bis(2,6-di-t-butylphenol), p-amino phenol, N-lauryloxy-p-amino phenol,4,4′-thiobis(3-methyl-6-t-butyl phenol), bis [o-(1,1,3,3-tetramethylbutyl)phenol] sulfide, 4-acetyl-β-resorcylic acid, A-stagep-t-butylphenolformaldehyde resin, 4-dodecyloxy-2-hydroxybenzophenone,3-hydroxy-4-(phenylcarbonyl) phenryl palmitate, n-dodecyl ester of3-hydroxy-4-(phenyl carbonyl) phenoxyacetic acid, and t-butyl phenol.

[0146] The use of epoxy compounds in an amount of 0.01-5% in the polymercompositions is also valuable. Examples of such epoxy compounds includeepoxidized soya bean oil, epoxidized lard oil, epoxidized olive oil,epoxidized linseed oil, epoxidized castor oil, epoxidized peanut oil,epoxidized corn oil, epoxidized tung oil, epoxidized cottonseed oil,epichlorhydrin/bis-phenol A resins, phenoxy-propylene oxide,butoxypropylene oxide, epoxidized neopentylene oleate, glycidylepoxystearate, epoxidized α-olefins, epoxidized glycidyl soyate,dicyclopentadiene dioxide, epoxidized butyl toluate, styrene oxide,dipentene dioxide, glycidol, vinyl cyclo-hexene dioxide, glycidyl etherof resorcinol, glycidol ether of hydroquinone, glycidyl ether of1,5-dihyroxynaphthalene, epoxidized linseed oil fatty acids, allylglycidyl ether, butyl glycidyl ether, cyclohexane oxide,4-(2,3-epoxypropoxy) acetophenone, mesityl oxide epoxide,2-ethyl-3-propyl glycidamide, glycidyl ethers of glycerine,pentaerythritol and sorbitol, and 3,4-epoxycyclohexane-1, 1-dimethanolbis-9,10-epoxystearate.

[0147] Likewise there can be used organic phosphites in an amount of0.01 to 10%, preferably 0.1-5% of the halogen containing resins. Theorganic phosphites contain one or more, up to a total of three, aryl,alkyl, aralkyl and alkaryl groups, in any combination. The term“trialkylaryl” is inclusive of alkyl, aryl, alkaryl and aralkylphosphites containing any assortment of alkyl, aryl, alkaryl and aralkylgroups. Exemplary are triphenyl phosphite, tricresyl phosphite,tri(dimethylphenyl) phosphite, tributyl phosphite, trioctyl phosphite,tridodecyl phosphite, octyl diphenyl phosphite, dioctyl phenylphosphite, tri(octyl-phenyl) phosphite, tri(nonylphenyl) phosphite,tribenzyl phosphite, butyl dicresyl phosphite, octyl di(octyl-phenyl)phosphite, tri(2-ethyl-hexyl) phosphite, tritolyl phosphite,tri(2-cyclohexylphenyl) phosphite, tri-alpha-naphthyl phosphite,tri(phenylphenyl) phosphite, and tri(2-phenylethyl) phosphite.

[0148] Likewise there can be include,d polyol stabilizers for vinylchloride resins in an amount of 0.01-10%. Thus there can be includedglycerol, sorbitol, pentaerythritol and mannitol.

[0149] Nitrogen containing stabilizers such as dicyandiamide, mel-amine,urea, formoguanamine, dimethyl hydantoin, guanidine, thio-urea,2-phenylindoles, aminocrotonates, N-alkyl and N-phenyl substitutedmaleimides, wherein the alkyl group has from 1 to 4 carbon atoms, andthe like also can be included in amounts of 0.1-10%. There can even beincluded conventional lubricants for vinyl chloride resins such as lowmolecular weight polyethylene, i.e. polyethylene wax, fatty acid amides,e.g. lauramide and stear-amide, bisamides, e.g. decamethylene, bisamide, and fatty acid esters, e.g. butyl stearate, glyceryl stearate,linseed oil, palm oil, decyloleate, corn oil, cottonseed oil,hydrogenated cottonseed oil, etc.

[0150] The stabilizer compositions of this invention may be prepared byblending the components thereof in any convenient manner which producesa homogeneous mixture, such as by shaking or stirring in a container.Likewise, the stabilized compositions of this invention can beincorporated in the halogen-containing organic polymer by admixing thestabilizer composition and polymer, such as, for example, in anappropriate mill or mixer or by any other of the well-known methodswhich provide uniform distribution of the stabilizer throughout thepolymer.

[0151] The stabilizer compositions of this invention are employed in anamount sufficient to impart the desired resistance to heat deteriorationto halogen-containing organic polymers. It will be readily apparent toone of ordinary skill in the art, that the precise amount of stabilizercomposition used will depend upon several factors, including, but notlimited to, the particular halogen-containing organic polymer employed,the temperature to which the polymer will be subjected, and the possiblepresence of other stabilizing compounds. In general, the more severe theconditions to which the halogen-containing organic polymer issub-jected, and the longer the term required for resisting degradation,the greater will be the amount of stabilizer composition required.Generally, as little as about 0.20 part by weight of the stabilizercomposition per hundred parts by weight of halogen-containing organicpolymer will be effective. While there is no critical upper limit to theamount of stabilizer composition which can be employed, amounts inexcess of about 10 parts by weight of halogen-containing organic polymerdo not give an increase in effectiveness commensurate with theadditional amount of stabilizer employed.

[0152] The following examples further illustrate the preparation ofblocked mercaptans of this invention, the preparation of stabilizercompositions of this invention, and the advantages of said blockedmercaptans and stabilizer compositions.

EXAMPLES 1-14

[0153] The starting materials, the procedure for preparing the latentmercaptans and the percent of residual —SH groups in the latentmercaptan are given in TABLE 9. The total color change of PVCcompositions containing said latent mercaptans as part of stabilizercompositions in contrast to that of PVC compositions which are otherwisethe same but without the latent mercaptan of this invention are given inTABLE 10.

[0154] A standard PVC pipe formulation containing: INGREDIENT AMOUNT PVC(Shintech SE950) 100.00 Calcium carbonate 5.00 phr Titanium dioxide 1.00″ Calcium stearate 0.60 ″ Oxidized polyethylene 0.15 ″ Paraffin wax 1.20″ Tin mercaptide of a mercaptoalkyl 0.25 ″ carboxylate

[0155] was processed as the Control on a standard two-roll mill at 199°C. with chips taken at one-minute intervals. Then the same formulationexcept for the addition of the indicated amount of latent mercaptan wasalso processed on the same roll at the same temperature, taking chips atthe same intervals. The total color change (dE), relative to a whitetile standard, was measured using a Hunter calorimeter. The dE valuesgiven in TABLE 10 for the Control are averages of the values measured inthe 12 tests which paralleled the tests of the stabilizer compositionsof Examples 1-12.

EXAMPLES 15-18

[0156] The standard PVC pipe formulation of Examples 1-14 was used andthe heat stabilization afforded by latent mercaptans of FORMULAS 4, 2,and 18 were tested at different levels as shown in Table 11. TABLE 9Example No. FORMULA Procedure % SH 1 2 A 0.31 2 3 A 0.10  3* 4 A 0.17 410 A 0.10 5 11 B 0.10 6 12 C 0.20 7 13 B 13.2 8 14 A 0.10 9 15 E 0.10 10 16 D 0.35  11 17 D 0.30   12** 18 A 0.25  13 21 A 0.30  14 25 C 0.20

[0157] TABLE 10 Example dE at one-minute Intervals phr 1 2 3 4 5 6 7 8 910 Control — 5.6 7.2 8.1 9.4 11.2 13.7 17.0 20.8 23.8 25.7 1 0.10 3.94.2 4.6 5.5 8.3 12.1 16.6 20.0 23.6 26.7 2 0.15 4.0 3.9 4.7 5.5 7.0 10.314.0 17.6 22.1 26.2 3 0.15 4.0 4.7 4.6 5.2 6.7 8.5 11.3 14.1 18.0 21.3 40.28 3.9 5.0 5.5 6.1 7.6 11.7 16.7 20.5 24.2 25.5 5 0.25 5.3 6.2 6.8 7.79.3 13.8 18.3 22.1 24.2 25.5 6 0.04 3.0 3.5 4.4 5.8 9.5 13.8 18.3 22.223.9 25.6 7 0.12 4.9 5.7 6.5 6.8 7.6 8.9 11.1 14.3 17.1 20.9 8 0.15 6.66.7 7.0 7.2 7.8 9.9 12.3 16.3 20.1 23.3 9 0.20 4.3 5.3 6.3 8.5 10.9 14.618.6 22.2 24.5 26.8 10 0.30 4.9 5.2 5.6 6.5 7.5 10.6 14.8 18.5 22.0 24.211 0.25 6.3 6.6 6.5 7.0 8.2 11.6 16.0 19.4 22.0 23.1 12 0.10 3.5 4.3 5.46.4 8.0 10.7 14.1 17.4 21.4 24.7 13 0.10 4.1 4.7 4.7 5.5 6.7 10.0 13.817.4 20.1 22.8 14 0.10 4.7 5.6 6.0 6.6 7.3 8.2 16.3 12.9 16.1 18.6

[0158] TABLE 11 Example dE at One-minute Intervals FORMULA phr 1 2 3 4 56 7 8 9 10 Control — — 5.6 7.2 8.1 9.4 11.2 13.7 17.0 20.8 23.8 25.7 154 0.28 4.2 4.6 4.9 5.9 7.6 10.7 13.0 16.5 20.2 24.6 16 2 0.28 3.8 4.04.7 5.3 7.6 10.0 13.2 16.8 21.5 26.3 17 4 0.03 4.4 5.4 5.9 6.4 6.6 7.810.0 12.4 14.7 17.1 18 18 0.05 3.5 5.4 5.3 6.2 7.5 8.7 10.2 12.7 10.317.8

EXAMPLE 19

[0159] A standard clear PVC formulation containing: INGREDIENT AMOUNTPVC (OCCIDENTAL 190) 100.00 PROCESS AID 1.50 phr IMPACT MODIFIER 6.00 ″LOXIOL G-16 1.00 ″ LOXIOL G-70 0.70 ″ OXIDIZED POLYETHYLENE 0.20 ″EPOXIDIZED SOYBEAN OIL 1.00 ″ METHYLTINTHIOGLYCOLATE 1.25 ″

[0160] was processed as a Control on a standard two-roll mill (30F/40R)at 187° C. with chips taken at two-minute intervals. Then the sameformulation except for decreased stabilizer level and the addition ofthe amount of latent mercaptan shown below was also processed on thesame roll at the same temperature, taking chips at the same intervals.The total color change (dE) was measured versus a white tile standardusing a Hunter colorimeter. INGREDIENT AMOUNT (PHR)METHYLTINTHIOGLYCOLATE 1.00 COMPOUND #4 0.25

[0161] TABLE 12 dE at Two Minute Intervals 2 4 6 8 10 12 14 16 18 20 22Control 15.0 15.9 17.1 17.3 18.7 20.1 21.5 23.6 26.8 31.7 38.2 Ex. 1915.1 14.6 15.1 15.4 15.7 16.9 18.5 20.7 23.7 27.3 34.5

EXAMPLE 20

[0162]¹H-NMR spectroscopy was used to determine the molecular structureof 2-S-(tetrahydropyranyl)thioethyldecanoate (FORMULA 24) which wasprepared by adding 42.0 grams (0.50 mole) of 3,4-dihydropyran to 112.2grams (0.50 equivalent) of mercaptoethyldecanoate (14.7% SH) over aperiod of 45 minutes while maintaining a nitrogen atmosphere and atemperature below 35° C. and then heating it to 50° C. and holding thattemperature for 1.5 hours. After cooling the solution, it was washedwith two 200 ml portions of a 10% sodium bicarbonate solution in water,followed by a 200 ml wash with water. The organic layer was dried withMgSO₄ to yield a light yellow liquid having an SH content of less than0.5 percent as determined by titration with a 0.100 N iodine solution inisopropanol. The ¹H-NMR (CDCl₃, δ) spectrum was: 2.3 (2H, t, —C(═O)—CH₂—CH₂), 2.8 (2H, m, —S—CH ₂—CH₂—), 4.2 (2H, m, —S—CH₂CH ₂—O—), 4.9 (1H,m, —O—CH(—S—CH₂—)—CH₂—CH₂—). The total color change (dE) of a PVCcomposition containing 0.13 phr of the latent mercaptan of this examplewas measured versus a white tile standard using a Hunter calorimeter atone mintue intervals. At one minute, it was 4.2; at five mintues, it was8.4.

EXAMPLE 21

[0163]¹H-NMR spectroscopy was used to determine the molecular structureof 1-S-(2-hydroxyethylthio)-1-phenylmethane (FORMULA 11) which wasprepared by adding 135.0 grams of a 20% methanol solution of sodiummethoxide to 39.1 grams (0.50 mole) of 2-mercaptoethanol and 63.3 (0.50mole) grams of benzyl chloride under nitrogen over a period of 45minutes while keeping the temperature below 50° C., then heating thesolution to 60° C. and holding it there for 6 hours. After cooling thesolution, it was washed with two 200 ml portions of water, dried withmagnesium sulfate, and stripped of solvent at 90° C. and 10 mm Hg toyield a light yellow liquid having an SH contemt of less than 0.5percent as determined by titration with a 0.100N iodine solution inisopropanol. The ¹H-NM (CDCl₃, δ) spectrum was: 2.6 (2H, t, —S—CH₂—CH₂—OH), 3.6 (2H, t, —CH₂—CH ₂—OH), 3.7 (2H, s, Ar—CH ₂—S—), 7.3 (5H,m, Ar—H); the ¹³C-NMR (CDCl₃, δ) spectrum was 33.9 (—S—CH₂—) 35.8(Ar—CH₂—) and 126.9-138.6 (Ar).

EXAMPLE 22

[0164]¹H-NMR spectroscopy was used to determine the molecular structureof 1-S-(2-hydroxyethylthio)-1-(2-hydroxyphenyl)methane (FORMULA 12)which was prepared by heating a stirred mixture of 31.5 grams (0.40mole) of 2-mercaptoethanol and 50 grams (0.40 mole) of 2-hydroxy benzylalcohol in 75 grams of toluene to 40° C. under nitrogen and adding 0.21gram of 70% methanesulfonic acid, heating it to 65° C. and holding itthere for 45 minutes. After cooling the solution, it was washed with 100mls of 10% aqueous sodium bicarbonate and 100 mls of water, dried withmagnesium sulfate, and stripped of solvent at 50° C. and 10 mm Hg toyield a tan viscous oil having an SH content of less than 0.3 percent asdetermined by titration with a 0.100N iodine solution in isopropanol.The product was purified by column chromatography through silica gelusing ethyl acetate/methanol as the elution solvent to obtain a lightyellow oil. The ¹H-NMR (CDCl₃, δ) spectrum was: 2.5 (2H, t, —S—CH₂—CH₂—), 3.6 (2H, t, —CH₂—CH ₂—OH), 3.7 (2H, s, Ar—CH ₂—S—), 6.6-7.2(5H, m, Ar—H); the ¹³C-NMR (CDCl₃, δ) spectrum was 31.1 (—S—CH₂CH₂—),33.5 (Ar—CH₂—S—), 61.1 (—CH₂ CH₂—OH and 116.5-154.3 (Ar).

EXAMPLE 23

[0165]¹H-NMR spectroscopy was used to determine the molecular structureof 1-S-(2-hydroxyethylthio)-1-methyl-1-N-pyrrolidinonylmethane (FORMULA2) which was prepared by adding 55.57 grams (0.50 mole) of 1-vinyl-2pyrrolidinone with stirring to a solution of 39.06 grams (0.50 mole) of2-mercaptoethanol and 0.14 gram of 70% methanesulfonic acid whilemaintaining the temperature below 40° C. and an atmosphere of nitrogenin the reaction vessel. The reaction mixture was heated to 60° C. andheld there for one hour. After cooling the solution, it was diluted with75 mls of diethyl ether, washed with two 100 ml portions of water and 25mls of saturated aqueous sodium bicarbonate, dried with magnesiumsulfate, and stripped of solvent at 50° C. and 10 mm Hg to yield a lightyellow oil having an SH content of less than 0.5 percent as determinedby titration with a 0.100N iodine solution in isopropanol. The ¹H-NMR(CDCl₃, δ) spectrum was: 1.4 (3H, d, CH ₃—CH<), 2.1 (2H, q, ≦N—CH₂—CH₂—CH₂—), 2.4 (2H, t, —S—CH ₂—CH₂—) , 2.5 (2H, t, —CH ₂—C(═0)−), 3.4 (2H,t, —CH₂—CH ₂—N<), 3.7 (2H, t, —CH₂—CH ₂—OH), 5.6 (1H,q, ≦N—CH(—CH₃)—S—);the ¹³C-NMR (CDCl₃, δ) spectrum was 17.7 (≦CH—CH₃), 19.2(—CH₂—CH₂—CH₂—), 31.3 (CH₂—CH₂—C (═0)−), 33.4 (—S—CH₂CH₂—), 41.8(≦N—CH₂—CH₂—), 51.5 (≦N—CH—(CH₃)—S—), 61.6 (—S—CH₂ CH₂—OH). 175.5(—CH₂C(═0)—N<).

EXAMPLE 24

[0166] To 28.4 grams (0.36 mole) of 2-mercaptoethanol under nitrogen,there was added 0.22 gram of p-toluenesulfonic acid, immediatelyfollowed by the addition of 60.0 grams (0.36 mole) of cresyl glycidylether with stirring over a period of 60 minutes while maintaining thetemperature at 50° C. The mixture was then heated to 65° C. and heldthere for 2.5 hours. After cooling, the solution was-washed with sodiumbicarbonate two-150 ml portions of water containing 25 mls of saturatedaqueous sodium bicarbonate solution, then dried with magnesium sulfateto yield a clear oil with <0.4% SH as determined by titration with 0.100N iodine solution in isopropanol. The molecular structure of theproduct, 2-hydroxy-3-(2-hydroxyethylthio)propyl o-methylphenyl ether(FORMULA 16), was determined by ¹H-NMR and ¹³C-NMR spectroscopy. ¹H-NMR(CD₃COCD₃, δ): 2.2 (3H, s, ArCH ₃), 2.8 (4H, m, —CH ₂—S—), 3.7 (2H, m,—CH ₂—OH), 4.1 (2H, dd, Ar—O—CH ₂—), 4.6 (1H, m, —CH(OH)—, 6.8-7.2 (4H,m, Ar—H); ¹³C-NMR (CD₃COCD₃, δ): 16.3 (Ar—CH₃), 36.8 (—S—CH₂—), 62.3(—CH₂—OH), 70.1 (≦CH—OH), 70.5 (Ar—O—CH₂—), 111.9-157.8 (Ar).

EXAMPLES 25 & 26

[0167] As another aspect of this invention, it has been discovered thatantioxidants activate the latent mercaptans to enhance the heatstability of PVC compositions during processing. The PVC pipeformulations of Example 25 (latent mercaptan alone) and Example 26(latent mercaptan+an antioxidant) are compared with the Control andComparative Example 1 (CE 1) in TABLE 14. Each was processed on astandard two-roll mill at 199° C. Chips of the PVC formulation weretaken at one-minute intervals. The enhanced heat stability of theformulation of Example 26 is evident. As a comparison of the results forthe Control and CE 1 shows, the antioxidant does not, by itself, enhancethe effect of the alkyltin mercaptide. EXAMPLE INGREDIENT Control 25 26CompEx 1 PVC (Shintech SE950) 100.00 100.00 100.0 100.00 Calciumcarbonate 5.00 5.00 5.00 5.00 Titanium dioxide 1.00 1.00 1.00 1.00Calcium stearate 0.60 0.60 0.60 0.60 Oxidized polyethylene 0.15 0.150.15 0.15 Paraffin wax 1.20 1.20 1.20 1.20 Alkyltin mercaptide 0.25 0.250.25 0.25 of a mercaptoalkyl carboxylate Latent mercaptan* 0.00 0.150.15 0.00 IRGANOX 1010 antioxidant 0.00 0.00 0.20 0.20

[0168] TABLE 14 dE values at One Minute Intervals Ex. No. 1 2 3 4 5 6 78 9 10 11 Cont. 6.2 7.5 8.3 9.5 11.2 13.2 16.8 20.6 23.7 25.2 27.2 254.0 4.8 5.0 5.6 7.1 9.4 12.7 15.6 18.7 22.0 25.2 26 4.3 4.6 5.0 5.2 5.97.7 10.2 13.2 15.8 18.8 21.5 CE 1 5.3 7.6 8.3 9.3 11.0 13.1 16.8 20.023.2 25.1 26.6

[0169] As was mentioned above, the latent mercaptans of this inventionare also intermediates for the preparation of primary heat stabilizers,anti-oxidants, anti-microbial agents, odor masks, and photostabilizers.Primary heat stabilizers, for example, may be made from latentmercaptans having a phenolic, carboxylate, or a free mercaptanfunctionality by reaction with a metal or organometal oxide, hydroxide,or halide such as calcium hydroxide, barium hydroxide, methyltintrichloride and dimethyltin dichloride. Phenols, for example, yieldcompounds having the general formula

AB_(b)

[0170] wherein A is Sn, Ba, Ca, Al, Mg, monoalkyltin, dialkyltin,trialkyl tin, B is

[0171] m and n are 0 or 1, X is aryl, alkaryl, or haloaryl, R¹ throughR⁶ are the same as above, R⁸ is o⁻ or S⁻, z is 1 or 2, and b is from 1to 4.

[0172] As another aspect of this invention then, a compound of theFormula AB_(b) wherein A is dibutyltin, B is

[0173] m=0, n=0, z=1; X is phenyl, R⁴ and R⁵ are hydrogen, R⁸ is o⁻, R¹is hydroxyethyl and b is 2,

[0174] was prepared by the reaction of dibutyltin oxide with1-S-(2-hydroxyethylthio)-1-(2-hydroxyphenylmethane) (FORMULA 12) asfurther described in Example 27.

EXAMPLE 27 AND COMPARATIVE EXAMPLE 2

[0175] Twenty grams (0.08 mole) of dibutyltin oxide, 29.61 grams (0.16mole) of 1-S-(2-hydroxyethylthio)-1-(2-hydroxyphenylmethane), and 150mls of toluene were heated under a nitrogen atmosphere in a round bottomflask equipped with a Dean-Stark trap. The azeotropic distillation ofwater was carried out at 108-111° C. and the theoretical amount (0.7 ml)was collected after about two hours. The toluene was removed bydistillation at 10 mm Hg and a maximum temperature of 110° C. A yellowoil having little or no odor was obtained. The theoretical tin contentis 19.7%; the tin content found was 20.2%. A satisfactory product ofthis invention was thus obtained.

[0176] In TABLE 15, the stabilization of a standard PVC pipe formulationby the product of Example 27 at a level of 0.25 phr is compared withthat of dibutyltin diphenate at the same level (Comparative Example 2,made according to the general procedure of Example 27 except that phenolwas substituted for the1-S-(2-hydroxyethylthio)-1-(2-hydroxyphenylmethane). The resultingformulations were processed on a standard two-roll mill at 199° C. withchips being taken at one-minute intervals. The standard formulation, asfollows, was tested as the Control: PVC (Shintech SE950) 100.00 Calciumcarbonate 5.00 Titanium dioxide 1.00 Calcium stearate 0.60 Oxidizedpolyethylene 0.15 Paraffin wax 1.20

[0177] TABLE 15 dE at One-minute Intervals Example 1 2 3 4 5 6 Control19.4 33.5 40.3 43.0 40.3 39.3 Comp Ex 2 12.4 22.1 33.0 35.7 35.7 34.1 277.9 15.3 21.7 29.5 36.8 41.3

EXAMPLE 28

[0178] To a solution containing 22.58 grams (0.106 mole)1-S-hydroxyethylthiol-1-(2-hydroxyphenyl)propane, 14.47 grams (0.053mole) 2-mercaptoethyl-(4-methoxybenzyl)thioacetate, 17.94 grams (0.177mole) triethylamine, and 50 ml of dichloromethane is added dropwise overa period of one hour at 8° C. a solution of 15.00 grams (0.053 mole) ofbutyltintrichloride in 50 ml dichloromethane with stirring under anitrogen atmosphere. The solution is then slowly warmed to 40° C. andheld for one hour after which it is cooled to room temperature,transferred to a separatory funnel, and washed twice with 150 ml ofwater. After drying with magnesium sulfate, the product is stripped ofsolvent at 50° C. under 15 mm pressure to yield an amber oil. Theproduct was analyzed for tin content, 14.5% (14.2% theory), andtitratable SH, 4.0% (4.0% theory). A satisfactory product of thisinvention was thus obtained. In the AB_(b) formula for this product, Ais monobutyltin, B is the same as in Example 27, and b is 3.

[0179] A standard pipe formulation containing the following components:INGREDIENT AMOUNT PVC (Shintech SE950) 100.00 Calcium carbonate 5.00 phrTitanium dioxide 1.00 ″ Paraffin wax 1.20 ″ Clacium stearate 0.60 ″Oxidized Polyethylene 0.15 ″

[0180] was processed with 0.27 phr of the above protected mercaptanstabilizer and in the absence of stabilizer (CONTROL) on a standardtwo-roll mill (30F/40R) at 199° C. with chips taken at one minuteintervals. The total color change (dE) was measured versus a white tilestandard using a Hunter calorimeter and is shown in Table 16. TABLE 16dE at One-minute Intervals Example 1 2 3 4 5 6 7 8 9 10 Control 19.030.8 37.4 41.5 41.4 41.8 41.9 38.6 37.6 36.2 28 5.8 8.0 9.7 11.0 12.915.2 17.1 19.4 22.3 24.3

[0181] Anti-oxidants also may be made from latent mercaptans having aphenolic or hydroxyl group by their reaction with phosphorus trichlorideor a phosphite having one, two, or three alkoxy, aryloxy, aralkoxy,alkaryloxy, or haloaryloxy groups to give a

PQ_(p)B_(3−p)

[0182] compound wherein P is phosphorus, Q is an alkoxy, aryloxy,aralkoxy, alkaryloxy, or haloaryloxy radical, p is 1 or 2 and B is

[0183] wherein n is 0 or 1; z is 1 or 2; R¹ through R⁶ are as above inFormula 1, X is aryl, haloaryl, or arylcycloalkyl, and R⁸ is 0.

[0184] Also, the latent mercaptans of this invention wherein theblocking or protecting group includes chemical functionality may provideadditional benefit in polymer processing and/or performance. Thedisagreeable odor generated by primary mercaptan-containing stabilizersduring the processing of PVC is masked by latent mercaptans exemplifiedby the compound of FORMULA 21⁻, the compound of FORMULA 25 and theirisomers and homologs, as otherwise defined by Formula 1, atconcentrations as small as about 0.01 part of the latent mercaptan perhundred parts of the halogenated polymer. Much larger amounts of thelatent mercaptan may, of course, be used but the maximum amountnecessary to effect the masking is about 0.1 phr and the preferredamount is about 0.05 phr. Thus, this invention provides a means formasking the odor of mercaptans while maintaining the function of themercaptan as a synergist for improved color-hold.

[0185] It also has been found that the latent mercaptans of thisinvention are useful as the sole heat stabilizer ior a flexible PVCformulation. Suitably, the amount of the latent mercaptan for this usemay be from about 1% to about 10% by weight of the total weight of thestabilized PVC composition. This use of the latent mercaptans of thisinvention is exemplified in Examples 29 and 30 and by the test resultsshown in Table 17.

EXAMPLES 29 AND 30

[0186] A standard flexible PVC formulation containing: INGREDIENT AMOUNTPVC (GEON 30) 100.0 DIOCTYL PHTHALATE 25.0 phr EPOXIDZED SOYBEAN OIL 4.0″ OXIDIZED POLYETHYLENE 0.2 ″ STEARIC ACID 0.5 ″

[0187] was processed using a Brabender Plasticorder at 200° C./80 rpmwith chips being taken at two minute intervals. Then the sameformulation except for the addition of 5.0 phr of the latent mercaptanof the Formula indicated in Table 17 was also processed at the sameintervals. The total color change (dE) was measured versus a white tilestandard using a Hunter calorimeter.

EXAMPLE 31

[0188] A standard flexible PVC formulation containing: INGREDIENT AMOUNTPVC (GEON 30) 100.00 DIOCTYL PHTHALATE 25.00 phr EPOXIDIZED SOYBEAN OIL4.00 ″ STEARIC ACID 0.50 ″ OXIDIZED POLYETHYLENE 0.20 ″ HYDROTALCITE2.00 ″

[0189] was processed using a Brabender Plasticorder at 200° C./80 rpmwith chips taken at two minute intervals. Then the same formulationexcept for a decreased part level of hydrotalcite, 1.00 phr, inconjunction with latent mercaptan (CMPD #4), 1.00 phr, was alsoprocessed at the same intervals. The total color change (dE), measuredversus a white tile standard using a Hunter calorimeter, is shown inTable 18. TABLE 17 dE at Two-minute Intervals Example 2 4 6 8 10 12 1416 18 20 22 Control 49.4 73.3 78.1 80.3 78.3 77.3 77.9 76.2 77.7 83.582.7 29 28.3 41.0 44.6 48.6 48.4 52.0 51.6 50.5 52.0 50.2 51.5 Formula#4 30 33.0 43.7 47.4 49.3 50.0 51.4 53.1 55.0 60.4 64.5 67.2 Formula #18

[0190] TABLE 18 dE at Two-minute Intervals Ex. 2 4 6 8 10 12 14 16 18 2022 24 Cont. 30.0 36.3 42.3 48.3 52.3 55.8 66.0 82.9 84.5 CHARRED — 3128.5 36.0 42.2 44.9 45.2 47.4 58.2 73.5 73.7 70.7 68.7 66.3

[0191] The use of the latent mercaptans of this invention along with amixed metal heat stabilizer for flexible PVC formulations is shown inthe following example.

EXAMPLE 32

[0192] A standard flexible PVC formulation containing: INGREDIENT AMOUNTPVC (GEON 30) 100.0 DIOCTYL PHTHALATE 25.0 phr EPOXIDIZED SOYBEAN OIL4.0 ″ OXIDIZED POLYETHYLENE 0.2 ″ STEARIC ACID 0.5 ″ Ba/Zn PHENATE 2.5 ″

[0193] was processed as a Control using a Brabender Plasticorder at 200°C./80 rpm with chips being taken at two minute intervals. Then the sameformulation except for the addition of 2.0 phr of the latent mercaptanof Formula 4 was also processed at the same intervals. The total colorchange (dE) was measured versus a white tile standard using a Huntercalorimeter.

EXAMPLE 33

[0194] A flexible PVC formulation, similar to that of Example 32 exceptthat the amounts of dioctyl phthalate and epoxidized soy bean oil were40 and 8.58 phr, respectively, and the phenate was replaced by a mixtureof a methyltin carboxylate (0.60 phr) and a zinc carboxylate (0.27 phr)was used as a Control and 0.75 phr of the latent mercaptan of Formula 4was added to exemplify this invention. Each was processed as in Example32 except that the Plasticorder was operated at 60 rpm. The colorchanges of the formulations of Examples 32 and 33 are given in Table 19.TABLE 19 Example dE at Two-minute Intervals Minutes 2 4 6 8 10 12 14 1618 20 22 Control (32) 23.1 21.1 20.8 20.9 19.9 20.8 24.7 27.2 33.2 41.251.2 32 21.4 21.1 20.9 21.9 22.6 25.8 26.0 31.1 35.0 39.2 42.9 Control(33) 26.1 27.4 27.6 29.2 30.1 31.6 33.6 33.5 38.1 38.8 39.5 33 24.8 24.124.3 24.3 23.7 24.7 25.5 24.8 26.7 26.3 28.0 dE at Two-minute IntervalsMinutes 24 26 28 30 32 34 36 38 Control (CEARRED) 32 43.8 48.5 51.1 52.355.5 61.5 74.0 (CHARRED)

[0195] Example 34 below illustrates the use of a hybrid mercaptan ofthis invention which contains both a blocked mercapto group and a freemercaptan group. The hybrid structures, as in FORMULA 13 above, functionas ligands for metallic-based stabilizers and as heat stabilizers bythemselves. Table 20 shows the improved early color when the hybrid isused.

EXAMPLE 34 AND COMPARATIVE EXAMPLE 3

[0196] A standard PVC pipe formulation containing: INGREDIENT AMOUNT PVC(Shintech SE 950) 100.00 Calcium carbonate 5.00 phr Titanium dioxide1.00 ″ paraffin wax 1.20 ″ Calcium stearate 0.60 ″ Oxidized polyethylene0.15 ″ Tin mercaptide of a mercapto- 0.25 ″ alkyl carboxylate

[0197] was processed as a Control on a dynamic two-roll mill at 199° C.(30F/40R) with chips being taken at one minute intervals. Then the sameformulation except for the addition of 0.11 phr of2-mercaptoethylcaprate (Comparative Example 3) or 0.12 phr of tie latentmercaptan of FORMULA 13 was processed at the same intervals. The totalcolor change (dE) was measured versus a white tile standard using aHunter calorimeter. TABLE 20 dE at One-minute Intervals Example 1 2 3 45 6 7 8 9 10 11 Control 5.7 7.6 8.8 9.6 11.4 13.1 16.5 19.7 22.9 25.226.6 CE 3 6.0 7.0 7.4 8.1 9.2 10.5 12.7 14.8 18.0 21.7 24.6 34 4.9 5.76.5 6.8 7.6 8.9 11.1 14.3 17.1 20.9 24.3 Formula #13

[0198] Latent mercaptans exemplified by the compounds of FORMULAS 12 and20 have anti-oxidant properties that may find use in improving polymerprocessing and polymer performance. A compound of FORMULA 23 acts as aphotostabilizer in a polymer to retard discoloration and loss ofphysical properties caused by ultra-violet radiation.

[0199] The tendency of a free mercaptan to deactivate a biocide in aproduct containing a heat stabilizer composition as well is negated bythe use of a latent mercaptan of this invention in combination with ametal-based stabilizer as the heat stabilizer composition. The latentmercaptan prepared by the reaction of 3,4-dihydropyran and2-mercaptoethanol (Formula 4), for example, when tested at a level of0.5 phr in vinyl films containing dibutyltin bis(2-phenylphenate) had nodetrimental effect on the anti-microbial activity of OBPA and Vinyzene®antimicrobials against staphylococcus aureus and klebsiella pneumoniaebacteria and a fungal mix including aspergillus niger, penicilliumpinophylium, chaetomium globosum, aureobasidium pullulans, andgliocladium virens.

[0200] A novel, commercially attractive method for making highly activePVC heat stabilizers which often function also as anti-oxidants, UVstabilizers, odor masks, and/or anti-microbial agents has beendeveloped. It is cost-effective and straightforward. The methodcomprises the reaction of a para-substituted phenol with formaldehydeand an alkali metal hydroxide in dilute aqueous solution at atemperature up to about 60° C., preferably a maximum of about 50° C.,and still more preferably from about 35° to about 50° C. Thecondensation is quenched by cooling the reaction mixture below 20° C. toas low as about 0° C., the mixture is neutralized, the resultantcondensate is isolated without further purification and is furthercondensed with a mercaptan-containing compound such as is describedhereinabove according to Procedure C, also described hereinabove. On anequivalent weight basis, the ratio of the phenol to formaldehyde is from1:1 to about 1:1.25 and the ratio of the phenol to alkali metalhydroxide is about 1:1 but a 5 to 10% excess may be used. The totalconcentration of the phenol and formaldehyde reactants in the aqueoushydroxymethylation of the phenol is from about 25 to about 50% byweight. Examples of suitable phenols include bisphenol A,4,4′-dihydroxydiphenyl sulfone (bisphenol S), p-nonylphenol,p-tert-butylphenol, 2,4-di-tert-butylphenol, p-methoxyphenol,p-propylphenol, and p-cresol. Typical sources of formaldehyde includeaqueous solutions thereof, paraformaldehyde, neat formaldehyde, andcyclic oligomers thereof.

[0201] Examples 35-37 below illustrate the novel method and the activityof the latent mercaptans produced is shown in Tables 21 and 22.

EXAMPLE 35

[0202] A nitrogen atmosphere is maintained in a 500 ml 3-neck flaskequipped with a condenser and a thermocouple while 20.0 grams (0.122mole) of 4-allyl-2-methoxyphenol (also known as eugenol) and 100 ml of5.14 weight/volume % of of aqueous sodium hydroxide solution are mixedwith stirring while maintaining the temperature of the reaction mixtureunder 35° C. When the mixture becomes homogeneous, 12.36 grams (0.153mole) of 37% aqueous formaldehyde solution is added over a ten minuteperiod at 35° C. and then the mixture is slowly heated to 50° C. andheld there for 3.5 hours, cooled, mixed with 100 ml of ethyl acetate andslowly acidified with dilute hydrochloric acid to a pH of 3 with rapidstirring while maintaining the temperature under 20° C. The organiclayer is separated and then combined with a 100 ml ethyl acetate extractof the aqueous layer. The ethyl acetate solution is dried with magnesiumsulfate and stripped of solvent at 45° C./15 mm Hg for one hour. Both ¹Hand ¹³C NMR confirm that the amber liquid residue conforms to thedesired intermediate, 4-allyl-2-methoxy-6-hydroxymethyl phenol. Then, anitrogen atmosphere is established in a 3-neck, 250 ml flask equippedwith a condenser and a thermocouple and maintained while 20.0 grams(0.103 mole) of the intermediate and 8.05 grams (0.103 mole) of2-mercaptoethanol, and 100 ml of toluene, are stirred until homogeneous.The solution is heated to 40° C., 0.06 gram of methanesulfonic acid isadded, and the solution is further heated to 65-70° C. for 3 hours. Thesolution is cooled to 25° C., transferred to a separatory funnel andwashed with a saturated sodium bicarbonate solution to neutrality, driedwith magnesium sulfate, and stripped at 40° C./5 mm Hg for one hour. Theresidue is an amber liquid of pleasant odor with 0.1% residual —SHcontent, as determined by 0.100 N iodine titration in isopropanol. Both¹H and ¹³C NMR confirm that the residue is4-allyl-2-methoxy-6-(2-hydroxyethyl-1S-thiomethyl)phenol as the majorproduct and unreacted intemediate as the remainder.

EXAMPLE 36

[0203] The general procedure of Example 35 was repeated except that 50grams (0.333 mole) of p-tert-butyl phenol was used, along with 14 grams(0.35 mole) of 98% sodium hydroxide and 33.73 grams (0.416 mole) of theformaldehyde solution to obtain the intermediate2-hydroxymethyl-4-tert-butyl phenol. The desired product,2-(2-hydroxyethyl)thiomethyl-4-tert-butyl phenol, was obtained from 17.2grams (0.095 mole) of the intermediate and 7.4 grams of the2-mercaptoethanol (0.095 mole) in 50 ml of toluene, along with 0.10 gramof the catalyst. Structural formula 26 for the product was confirmed by¹H and ¹³C NMR.

EXAMPLE 37

[0204] The general procedure of Example 35 was repeated except that 50grams of p-nonyl phenol (0.227 mole) was used, along with 9.73 grams(0.238 mole) of 98% sodium hydroxide and 23.0 grams (0.284 mole) of theformaldehyde solution to obtain the intermediate 2-hydroxymethyl-4-nonylphenol. The desired product, 2-(2-hydroxyethyl) thiomethyl-4-nonylphenol, was obtained from 23.85 grams (0.095 mole) of the intermediateand 7.4 grams of the 2-mercaptoethanol (0.095 mole) in 50 ml of toluene,along with 0.10 gram of the catalyst. Structural formula 27 for theproduct was confirmed by ¹H and ¹³C NMR.

EXAMPLES 38-39

[0205] A standard PVC pipe formulation containing: INGREDIENT AMOUNT PVC(Shintech SE 950) 100.00 Calcium carbonate 5.00 phr Titanium dioxide1.00 ″ Paraffin wax 1.20 ″ Calcium stearate 0.60 ″ Oxidized polyethylene0.15 ″ Dimethyltin mercaptide 0.25 ″ (ADVASTAB ® TM-599T)

[0206] was processed as a Control on a dynamic two-roll mill at 187° C.(30F/40R) with chips being takeriat one minute intervals. Theformulation of this invention (Example 39), made by the addition of 0.05phr of the product of Example 35 had a mild, yet decidedly pleasant odorduring processing on the two-roll mill under the same conditions. Thetotal color change (dE) and the Whiteness Index of each are shown inTable 21. TABLE 21 Exam- ple 1 2 3 4 5 6 7 8 9 10 dE at one minuteintervals Control 4.6 6.3 7.0 7.5 8.1 9.4 10.7 12.1 14.4 16.8 39 3.9 4.64.8 5.1 5.7 6.7 8.5 10.8 13.7 16.5 Whiteness Index at one minuteintervals Control 61.2 49.8 45.6 43.0 39.1 31.9 24.9 17.1 6.8 −6.5 3963.6 58.0 57.3 54.5 50.5 45.1 35.5 24.1 8.8 −5.2

EXAMPLE 40

[0207] The standard PVC pipe formulation of Examples 38-39 was againused as a Control and was processed on a dynamic two-roll mill at 187°C. (30F/40R) with chips being taken at one minute intervals. Theformulation of this invention made by the addition of 0.03 phr of theproduct of Example 36 was processed under the same conditions. The totalcolor change (dE) and the Whiteness Index of each are shown in Table 22.TABLE 22 Exam- ple 1 2 3 4 5 6 7 8 9 10 dE at one minute intervalsControl 4.4 6.1 6.6 7.4 7.9 8.7 10.1 11.6 13.1 15.9 40 3.6 4.4 4.3 4.85.3 6.5 8.0 10.6 13.3 15.5 Whiteness Index at one minute intervalsControl 59.8 51.7 47.9 43.2 40.2 35.8 27.5 19.6 11.7 −2.1 40 62.8 60.959.7 58.9 53.8 46.7 38.9 25.1 10.9 −0.3

EXAMPLE 41 AND COMPARATIVE EXAMPLE 4

[0208] The standard PVC pipe formulation of Examples 38-39 was againused as a Control. The formulation of this invention made by theaddition of 0.05 phr of the product of Example 37. For comparison, aformulation was made by the addition of 0.05 phr of nonylphenol to theControl. Each was processed on a dynamic two-roll mill at 187° C.(30F/40R) with chips being taken at one minute intervals. The totalcolor change (dE) and the Whiteness Index of each are shown in Table 23.TABLE 23 Exam- ple 1 2 3 4 5 6 7 8 9 10 dE at one minute intervalsControl 4.7 6.8 7.5 8.0 8.9 9.8 11.4 12.5 14.6 17.0 41 3.7 4.6 4.9 5.36.1 7.5 9.1 11.1 14.0 16.4 Comp Ex 4 4.7 6.6 7.2 7.5 8.1 9.1 9.9 11.513.7 15.9 Whiteness Index at one minute intervals Control 57.7 46.6 42.541.0 35.4 30.1 20.8 15.5 4.0 −7.6 41 63.5 60.4 56.4 55.9 50.0 41.9 33.523.3 7.5 −5.1 Comp Ex 4 59.4 48.0 44.8 43.2 39.2 33.8 29.8 20.9 9.2 −2.1

EXAMPLES 42-46

[0209] A standard flexible PVC formulation containing: INGREDIENT AMOUNTGeon 30 PVC resin 100.00 Dioxtyl phthalate 40.00 Epoxidized soybean oil8.58 Oxidized polyethylene 0.20 Stearic acid 0.50

[0210] was processed as the control on a standard two-roll mill at 199°C. with chips taken at two minute intervals. Then the same formulationexcept for the addition of the indicated amount of proctected mercaptanand N-substituted maleimides was also processed on the same two-rollmill under the same conditions. The total color change, dE, relative toa white tile standard, was measured using a Hunter calorimeter. EXAMPLEINGREDIENT AMOUNT CONTROL NONE — 42 Mixture of Formulas 4-9 2.50 phr 43N-ethylmaleimide 2.50 phr 44 Mixture of Formula 4-9 1.25 phrN-ethylmaleimide 1.25 phr 45 N-phenylmaleimide 2.50 phr 46 Mixture ofFormulas 4-9 1.25 phr N-phenylmaleimide 1.25 phr

[0211] TABLE 24 dE at two minute intervals Exam- ple 2 4 6 8 10 12 14 1618 20 Control 40.4 55.6 67.9 74.2 75.8 78.5 — — — — 42 25.9 35.0 44.145.9 47.8 49.2 49.8 50.6 51.1 52.1 43 28.6 41.2 52.9 58.9 59.6 63.5 — —— — 44 26.8 32.9 40.1 40.7 43.1 43.7 45.7 45.9 46.9 48.3 46 29.5 34.338.5 41.6 44.3 42.5 42.8 43.5 44.5 44.8

EXAMPLES 47-48 AND COMPARATIVE EXAMPLE 5

[0212] The stabilizing activities of 2-S-(tetrahydropyranyl)-thioethanol(Formula 4) and 2-S-(tetrahydropyranyl)thioethyl tallate, both preparedaccording to Procedure A hereinabove, and a thioether taught by Ludwigin U.S. Pat. No. 3,660,331 were compared by evaluating the color holdcapacities of flexible PVC compositions containing the following basecomposition and a stabilizer as indicated in Table 25 on a dynamictwo-roll mill at 350° F. (roll speed in rpm 30F/40R) on the yellownessindex, as shown in Table 25. COMPONENT (TM or abbrev.) PARTS BY WEIGHTPolyvinyl chloride (GEON 30) 100.0 Dioxtyl phthalate (DIDP) 40.0Epoxidized soybean oil (ESO) 5.0 Stearic acid 0.2 Oxidized polyethylene0.2. Ex. No. Stabilizer phr* 47 2-S-(2-hydroxyethylthio)tetrahydropyran2.00 Zinc 2-ethylhexanoate (18%_(wt) zinc) 482-S-(dodecylthio)tetrahydropyran (Ludwig) 2.00 Zinc 2-ethylhexanoate(18%_(wt) zinc) 0.05 CE 5 2-S-(2-hydroxyethylthio)tetrahydropyran 1.13**Zinc 2-ethylhexanoate (18%_(wt) zinc) 0.05

[0213] TABLE 25 Yellowness Index (YI) Time (Minutes) 5 10 15 20 25 30 3540 45 50 55 60 47 8.1 10.1 12.4 14.2 15.8 18.4 21.0 25.4 28.6 32.2 35.035.6 48 9.7 12.6 15.1 18.9 22.7 26.9 30.9 34.9 38.7 44.7 42.4 54.8 CE 59.4 11.0 13.6 13.8 17.7 20.1 24.6 29.8 34.6 40.9 45.9 55.2

EXAMPLE 49

[0214] 2-S-(tetrahydropyranyl)thioethyltallate is prepared by adding44.6 grams (0.53 mole) of 3,4-dihydropyran to 183.7 grams (0.50equivalent) of mercaptoethyltallate (9.0% SH) (made by the conventionalesterification of mercaptoethanol with tall oil acid) over a period of45 minutes in the presence of an acid catalyst while maintaining anitrogen atmosphere and a temperature below 35° C. and then heating itto 50° C. and holding that temperature for 1.5 hours. After cooling thesolution, it is washed with two 200 ml portions of a 10% sodiumbicarbonate solution in water, followed by a 200 ml wash with water. Theorganic layer is dried with MgSO₄ to yield a light yellow liquid havingan SH content of less than 0.5 percent as determined by titration with a0.100 N iodine solution in isopropanol.

EXAMPLES 50-53 AND COMPARATIVE EXAMPLES 6-9

[0215] The flexible PVC compositions in Table 26 contain the same basecomposition as in Examples 47 and 48 but without the oxidizedpolyethylene and with the indicated stabilizer. Ex. No. Stabilizer phr50 2-S-(2-hydroxyethylthio)tetrahydrpyran 1.13*** 512-S-(2-hydroxyethylthio)tetrahydropyran 2.00 CE 62-S-(dodecylthio)tetrahydropyran (Ludwig) 2.00 522-S-(tetrahydropyranyl)thioethyl tallate 2.00 Zinc 2-ethylhexanoate (18%zinc) 0.05 CE 7 2-S-(dodecylthio)tetrahydropyran (Ludwig) 2.00 Zinc2-ethylhexanoate (18% zinc) 0.05 CE 8 2-S-(dodecylthio)tetrahydropyran(Ludwig) 1.25† Zinc 2-ethylhexanoate (18% zinc) 532-S-(tetrahydropyranyl)thioethyl tallate 1.50 Conventional Ca/Znstabilizer 1.00 CE9 2-S-(dodecylthio)tetrahydropyran (Ludwig) 0.94††Conventional Ca/Zn stabilizer 1.00

[0216] TABLE 26 Yellowness Index (YI) Time (minutes) 5 10 15 20 25 30 3540 45 50 55 60 50 46.3 81.0 89.8 102.2 124.3 126.9 127.2 126.4 137.1132.2 122.4 113.2 51 48.4 81.9 93.6 103.0 112.1 112.9 122.2 131.2 124.2130.3 141.9 146.3 CE6 56.4 99.7 117.5 124.3 137.4 138.2 150.1 152.8153.7 159.9 160.6 164.6 52 11.1 12.3 13.3 14.9 15.5 17.3 18.0 24.3 32.940.2 51.6 67.6 CE7 10.5 12.0 14.6 17.1 20.7 24.2 28.9 34.0 40.3 48.054.5 63.3 CE8 9.9 11.4 13.2 17.1 22.5 27.1 36.7 42.7 51.5 58.9 72.1 85.053 11.2 12.7 14.7 16.8 18.5 20.5 23.6 28.9 37.0 54.9 106.2 burn CE9 10.812.4 14.9 17.4 19.1 21.0 26.4 36.4 46.3 67.1 burn

[0217] The dynamic thermal stability of the compositions of Examples 50and 51 and Comparative Example 5, as measured on the BRABENDERPLASTICORDER test device at 200° C. and 80 rpm, is shown in Table 27.TABLE 27 Dynamic Thermal Stability (minutes) 50 51.7 51 57.6 CE 6 57.3

EXAMPLE 54 AND COMPARATIVE EXAMPLE 10

[0218] An intermediate, 1-mercapto-2-hydroxypropyl isopropyl ether, wasmade by the reaction of H₂S with isopropyl glycidyl ether in thepresence of triethylamine. The intermediate was then reacted with3,4-dihydropyran according to Procedure A to make a latent mercaptan ofthis invention having the formula

[0219] wherein a is 1, m and n are 0, X is oxygen, R³ and R⁷ join with Xto form a heterocyclic moiety, and R¹ is alkoxy-hydroxyalkyl as itrelates to Formula 1. The stabilizing activity of theproduct,2-S-(tetrahydropyranyl)-1-isopropoxy-3-thio-2-propanol, was thencompared with) that of the 2-S-(dodecylthio)tetrahydropyran of Ludwig inPVC rigid pipe-making compositions at equal sulfur content levels and atequal stabilizer use levels. The Whiteness Index of the compositionsduring processing on a two-roll mill at 390° C. was measured atone-minute intervals. The stabilizer compositions given below were addedto the basic composition as shown in Table 28. The basic composition hadthe formulation: COMPONENT PARTS BY WEIGHT Polyvinyl chloride (k = 65)100.0 Calcium carbonate 5.00 Titanium dioxide 1.00 Paraffin wax 1.20Calcium stearate 0.60 Oxidized polyethylene 0.15 Ex. No. Stabilizer phrCE 10 2-S-(dodecylthio)tetrahydropyran 0.18 Tin mercaptide (ADVASTAB TM-599T) 54 2-S-(tetrahydropyranyl)1-isopropoxy- 0.15* -3-thio-2-propanolTin mercaptide (ADVASTAB TM- 0.20 599T) 552-S-(tetrahydropyranyl)1-isopropoxy- 0.18** -3-thio-2-propanol Tinmercaptide (ADVASTAB TM- 0.20 599T)

[0220] TABLE 28 PVC Color Hold (Whiteness Index) During Processing byTwo-Roll Mill @ 390° F. (minutes) 1 2 3 4 5 6 7 8 9 10 11 12 CE10 47.529.4 25.3 24.5 23.1 22.2 18.0 17.3 11.5 6.4 1.5 2.6 54 46.0 40.4 36.437.2 35.6 33.5 32.3 26.9 19.2 10.2 14.8 4.4 55 44.8 38.8 35.9 37.4 33.731.3 28.6 18.2 17.0 9.0 5.2 2.0

EXAMPLE 56 AND COMPARATIVE EXAMPLE 11

[0221] The whiteness index of rigid pipe-making PVC compositions havingthe above basic formulation and containing the following stabilizerformulations, measured as described above, is shown in Table 29. Ex. No.Stabilizer Compositions phr CE 11 2-S-(dodecylthio)tetrahydropyran 2.00Zinc octoate (18% zinc) 0.10 56 2-S-(tetrahydropyranyl)1-isopropxy- 2.00-3-thio-2-propanol Zinc octoate (18% zinc) 0.10

[0222] TABLE 29 PVC Color Hold (Whiteness Index) During Processing byTwo-Roll Mill @ 390° F. minutes 1 2 3 4 5 6 7 8 9 10 11 12 A 32.7 1.1−9.7 −8.6 −1.7 5.6 12.0 18.8 24.7 26.7 28.2 32.7 B 51.0 42.1 37.9 37.835.2 35.6 33.2 28.0 19.9 11.8 4.3 0.6

EXAMPLE 57

[0223] An intermediate, 1-mercapto-2-hydroxypropyl neodecanoate, wasmade by the addition of H₂S to glycidyl neodecanoate in the presence oftriethylamine. An exothermic reaction between 20 parts by weight (0.049mole) of the product and 4.29 parts by weight (0.051 mole) of3,4-dihydropyran in the presence of methane sulfonic acid raised thetemperature of the mixture to 60° C. before it was cooled rapidly to 40°C. and held there for 5 hours. The product was taken up in ethylacetate, washed with aqueous sodium bicarbonate solution, water andbrine, then dried with magnesium sulfate and stripped to yield 20.9parts of 2-S-(tetrahydropyranyl)3-thio-2-hydroxypropyl neodecanoatecontaining only 0.28% SH. The R¹ radical of this latent mercaptan isneodecanoyloxy-hydroxypropyl.

EXAMPLE 58

[0224] Five hundred mls of heptane and 168 grams (1.12 moles) of the1-mercapto-2-hydroxypropyl isopropyl ether of Example 54 were charged toa one-liter round bottom flask equipped with a condenser and Dean-Starkcollector. Then 144.9 grams (1.75 moles) of propionic acid and 1.7 gramsof methane sulfonic acid were added Twenty mls of water were collectedas the reaction mixture was heated at the 95° C. reflux temperature. Theproduct was chilled in an ice bath before excess acid was washed outwith aqueous sodium bicarbonate and brine. The product was dried withmagnesium sulfate and stripped to yield 217 grams of the isopropyl etherof 1-mercapto-2-propionoyloxypropane having a 13.89% SH content comparedto the theoretical value of 16.03%.

[0225] Ten grams (0.048 mole) of the ester and 3 drops of methanesulfonic acid were charged to a 100 ml round bottom flask equipped witha magnetic stirrer bar and an exothermic reaction raised the temperatureto 60° C. when 4.28 grams (0.051 mole) of 3,4-dihydropyran was added.The mixture was cooled and the reaction was continued at 40° C. forabout 19 hours. The product had an SH level of 0.43%. The2-S-(tetrahydropyranyl)-1-isopropoxy-3-thio-2-propionoyloxypropane hasthe formula

[0226] wherein a is 1, m and n are 0, z is 1, X is oxygen, R³ and R⁷join with X to form a heterocyclic moiety, and R¹ isisopropoxy-propionoyloxypropyl.

EXAMPLE 59

[0227] The adduct of 3,4-dihydropyran (DHP) andlauryl-3-mercaptopropionate was made by adding 8.6 grams (0.0102 mole)of the DHP over a 20 minute period to 29.0 grams (0.1 mole) of the esterand 0.1 gram of methane sulfonic acid in an ice-cooled reactor; theexotherm warmed the mixture to room temperature-And heat was applied tocontinue the eaction at 40-45° C. for 4 hours. The SH content of theproduct was only 0.44% by weight. The formula for the product is

[0228] wherein a is 1, m and n are 0, z is 1, X is oxygen, R³ and R⁷join with X to form a heterocyclic moiety, and R¹ isdodecyloxycarbonylethyl.

EXAMPLE 60

[0229] Bis[2-S-(tetrahydropyranyl)thioethyl malonate) was prepared bycharging 30 grams (0.18 mole) of bis-(2-mercaptoethyl malonate) and 0.08gram of methane sulfonic acid into a nitrogen-purged round bottom flaskand adding 21.87 grams (0.26 mole) of DHP over a 15 minute period. Theexotherm raised the temperature to 50° C. and the mixture was held atthat temperature for 30 minutes. Gas chromatography showed that about90% of the product was the desired latent mercaptan. Residual startimgmaterials were stripped off by heating the mixture to 40° C. at 35 mmHg. Filtration gave a 79% yield of clear, low-odor product having an SHcontent of less than 0.05%. The generic R¹ radical is alkylenebis-(carbonyloxyalkyl).

EXAMPLE 61

[0230] A latent mercaptan of this invention having a dihydroxypropylradical as the R¹ radical of Formula 1 was prepared by stirring 108.2grams (1.0 mole) of 3-mercapto-1,2-propanediol and 0.49 gram of methanesulfonic acid in an ice-water cooled round bottom flask while adding85.8 grams (1.02 moles) of DHP dropwise. The mixture was allowed to warmto room temperature for 15 minutes and then was heated to 40° C. for 4hours. The SH content of the product was less than 1%. The formula ofthe product, 2-S-(tetrahydropyranyl)3-thio-1,2 propanediol, is

[0231] wherein a is 1, m is 0, n is 1, z is 1, X is oxygen, R³ and R⁷join with X to form a heterocyclic moiety, and R¹ is dihydroxypropyl.

EXAMPLE 62

[0232] A latent mercaptan of this invention having a carboxyalkylradical as the R¹ of Formula 1 was prepared by cooling 69.44 grams (0.75mole) of thioglycolic acid and 0.33 gram of methane sulfonic acid in around bottom flask and adding 64.3 grams (0.765 mole) of DHP dropwise.The mixture was heated to 40° C. for 6 hours. The SH content was 0.06%.The formula for the 2-S-(tetrahydropyranyl)thioglycolic acid is

[0233] wherein a is 1, m and n are 0, z is 1, X is oxygen, R³ and R⁷join with X to form a heterocyclic moiety, and R¹ is carboxymethyl.

EXAMPLE 63

[0234] An intermediate,2-ethylhexyl mercapto-hydroxypropyl ether, wasmade by-the reaction of H₂S with 2-ethylhexyl glycidyl ether in thepresence of triethylamine. The intermediate was then reacted with3,4-dihydropyran according to Procedure A to make a latent mercaptan ofthis invention having the formula

[0235] wherein a is 1, m and n are 0, X is oxygen, R⁵ and R⁷ join with Xto form a heterocyclic moiety, and R¹ is ethylhexoxy-hydroxypropyl as itrelates to Formula 1. The SH content was 0.26% by weight.

EXAMPLE 64

[0236] An intermediate, 1-mercapto-2-hydroxypropyl butyrate, was made bythe reaction of H₂S with 10 grams of glycidyl butyrate wherein anexotherm raised the temperature from 15 to 47° C. in the presence of 50mls methanol and 9.7 mls triethylamine. The methanol and amine werestripped off and the residue extracted with ethyl acetate. The extractwas washed with 0.1N HCl and brine, dried with magnesium sulfite andstripped to yield 9.7 grams of the inermediate. Five grams of theintermediate was then reacted exothermally with 1.81 grams of3,4-dihydropyran with cooling according to Procedure A to make a latentmercaptan of this invention having the formula

[0237] wherein a is 1, m and n are 0, X is oxygen, R⁵ and R⁷ join with Xto form a heterocyclic moiety, and R¹ is butanoyl-hydroxypropyl as itrelates to Formula 1. The SH content was 0.33% by weight.

EXAMPLE 65

[0238] A chelating agent is made in an acid catalyzed reaction of 411.3grams (2 equivalents) of pyridoxine(3-hydroxy-4,5-dimethylol-2-methylpyridine) with 78 grams (1 equivalent)of mercaptoethanol and 138 grams (1 equivalent) of mercaptoethylether(HSCH₂CH₂OCH₂CH₂SH) to give a compound haying Formula 35 below:

[0239] wherein, with reference to Formula 1, a is 2, m is 1, n is 0, yis 2, X is phenyl, R¹ is ethoxyethyl, R⁶ is hydroxyl, one of the R⁷radicals on each ring is methyl, and the other ishydroxyethylmercaptomethyl.

EXAMPLE 66

[0240] An equimolar mixture of thioglycolic acid (124 grams) anddiethyleneglycol (106 grams) and a catalytic amount of methanesulfonicacid is heated to 100° C. at a pressure of 400 Torr and then heatedfurther to 120° C. as the pressure is reduced to 10 Torr over a periodof 2 hours to reduce the acid number to less than 10. The product iswashed and dried. The mono-ester is the predominant product. The mixtureof reaction products is then reacted with an excess of 3,4-dihyropyranto obtain an adduct having an —SH content less than 0.1% by weight. R¹of Formula 1 for the principal product ishydroxy(polyethoxy)carbonylmethyl. A bright white pipe is obtained fromthe extrusion of a rigid PVC pipe formulation containing this product asa heat stabilizer.

EXAMPLE 67

[0241] A product having a structure and properties similar to those ofthe product of Example 66 is obtained when the same procedure isfollowed with the exception of using triethyleneglycol in place ofdiethyleneglycol. In this case, R¹ of Formula 1 for the principalproduct is a hydroxy(polyalkoxy)carbonylalkyl radical wherein thepolyalkoxy chain has three units.

[0242] The acyloxy and benzoyloxy derivatives of thehydroxy(polyalkoxy)carbonylalkyl moiety are made by the conventionalesterification methods wherein the appropriate carboxylic acid isreacted with the hydroxyl group. Thetetrahydropyranyloxy(polyalkoxy)carbonylalkyl is made by a proceduresimilar to Procedure A hereinabove except for the use of the glycolderivative instead of a mercaptan. The etherification of thehydroxy(polyalkoxy) moiety with an alcohol such as propanol, benzylalcohol, or butanol is accomplished by heating a mixture of the glycolderivative, the alcohol, and an acid catalyst to drive off water ofcondensation.

EXAMPLE 68

[0243] The adduct of 3,4-dihydropyran and the methyl ester of N-acetylcysteine is made by adding 8.83 gram (0.105 mole) of the DHP dropwise to18 grams (0.102 mole) of the ester amd 0.1 gram of methanesulfonic acidin an ice-cooled reactor. The mixture is then warmed to 40-50° C. andheld there for 4 hours. The product is the methyl ester of2-tetrahydropyranyl-N-acetyl cysteine. The R¹ radical in Formula 1 ismethoxycarbonyl(N-acetoamido)alkyl

[0244] Articles of manufacture contemplated by this invention, e.g.pipe, film, and window profile, are formed from the stabilizedcompositions of this invention by any of the well-known conventionaltechniques for forming polymers into shaped articles.

[0245] While a few specific embodiments of this invention have beendisclosed in considerable detail, variations and modifications of theseembodiments can be effected without departing from the spirit and scopeof the invention as disclosed and claimed herein.

The subject matter claimed is:
 1. A polymeric composition comprising apolymer normally susceptible to heat-induced deterioration throughautoxidation and degradation products of a blocked mercaptan presentduring processing of the composition at an elevated temperature, saidproducts including a free mercaptan, wherein said blocked mercaptan hasthe structure:

wherein a is 0 or 1, m and n are 0 or 1; y=1 to 4; when y=1, z is 1 to4; and when y is more than 1, z is 1; R¹ is a hydroxyalkyl,dihydroxyalkyl, hydroxy(polyalkoxy) alkyl, alkoxyalkyl,hydroxyalkoxyalkyl, alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl),alkoxy(polyalkoxy)alkyl, carboxyalkyl, acyloxyalkyl,acyloxy(hydroxyalkyl), acyloxyalkoxyalkyl, acyloxy(polyalkoxy)alkyl,benzoyloxy(polyalkoxy)alkyl, alkylenebis-(acyloxyalkyl),alkoxycarbonylalkyl, alkoxycarbonylalkylenyl,hydroxyalkoxycarbonylalkyl, hydroxy(polyalkoxy)carbonylalkyl,alkoxy(polyalkoxy)carbonylalkyl, mercaptoalkyl, mercaptoalkylenyl,mercaptoalkoxycarbonyla lkyl, mercaptoalkoxycarbonylalkylenyl,alkoxycarbonyl(amido)alkyl, alkylcarbonyloxy (polyalkoxy) carbonylalkyl,tetrahydropyranyloxyalkyl, tetrahydopyranyloxy(polyalkoxy)carbonylalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, R⁶, and R⁷ are independently hydrogen, ahydroxyl, mercapto, acyl, alkyl, alkylenyl, aryl, haloaryl, alkaryl,aralkyl, hydroxyalkyl, mercaptoalkyl, hydroxyaryl, alkoxyaryl,alkoxyhydroxyaryl, hydroxyalkyl, mercaptoalkyl, mercaptoalkylenyl,mercaptoalkoxycarbonylalkylenyl, hydroxyaryl, arylcarbonyl,mercaptoaryl, carboxyalkyl, carboxyaryl, or acyl radical having from 1to 22 carbon atoms; X is aryl, haloaryl, alkaryl, hydroxyaryl,dihydroxyaryl, aralkaryl, alkoxyaryl, arylcycloalkyl, or a heteroatom,with the option that when a is 1 and m is 0, one of the R³ and R⁵radicals joins with R⁷ and X to form a heterocyclic moiety with X as aheteroatom selected from the group consisting of oxygen and sulfur, andwith the further option that when m is 1, R⁶ and R⁷ form a heterocyclicmoiety in conjunction with X as a nitrogen atom; with the proviso thatwhen X is aralkaryl, R⁶ and R⁷ are hydroxyl, a is 1 and m is 1, then zis 1 or 2, and with the further proviso that when R⁶≠hydroxyl ormercapto, z is
 1. 2. The composition of claim 1 wherein X is nitrogen, mis 1, R⁶ and R⁷ form a heterocyclic moiety in conjunction with X, and nis
 0. 3. The composition of claim 1 wherein R¹ is hydroxyalkyl.
 4. Thecomposition of claim 1 wherein X is nitrogen, m is 1, R⁶ is acyl, R⁴ isalkyl, R¹ is hydroxyalkyl, and n is
 0. 5. The composition of claim 1wherein X is oxygen, m is 0, R⁵ and R⁷ form a heterocyclic moiety inconjunction with X, and n is
 0. 6. The composition of claim 5 wherein R¹is hydroxyalkyl.
 7. The composition of claim 1 wherein R¹ isacyloxyalkyl,
 8. The composition of claim 1 wherein X is oxygen, m is 0,R⁵ and R⁷ form a heterocyclic moiety in conjunction with X, and n is 1.9. The composition of claim 8 wherein R¹ is hydroxyalkyl.
 10. Thecomposition of claim 8 wherein R¹ is acyloxyalkyl.
 11. The compositionof claim 1 wherein X is phenyl, and m and n are
 0. 12. The compositionof claim 11 wherein R¹ is hydroxyalkyl.
 13. The composition of claim 1wherein X is phenyl, R⁷ is hydroxyl, and m and n are
 0. 14. Thecomposition of claim 13 wherein R¹ is hydroxyalkyl.
 15. The compositionof claim 14 wherein R¹ is hydroxyethyl.
 16. The composition of claim 13wherein R¹ is acyloxyalkyl.
 17. The composition of claim 1 wherein X isphenyl, R⁷ is hydroxyl, m is 0, and n is
 1. 18. The composition of claim1 wherein X is oxygen, R⁷ is phenyl, m is 0, and n is
 1. 19. Thecomposition of claim 18 wherein R¹ is hydroxyalkyl.
 20. The compositionof claim 1 wherein wherein a is 1, m and n are 0, X is oxygen, R³ and R⁷join with X to form a heterocyclic moiety, and R¹ isalkoxy-hydroxyalkyl.
 21. The composition of claim 20 wherein R¹ isisopropoxy-hydroxyethyl.
 22. The composition of claim 1 wherein m is 0,X is alkoxyphenyl, and R⁷ is hydroxyl.
 23. The composition of claim 22wherein R¹ is hydroxyalkyl.
 24. The composition of claim 1 wherein X isoxygen, m is 0, n is 1, R⁵ is aryloxyalkyl, and R⁷ is hydrogen.
 25. Thecomposition of claim 1 wherein X is oxygen, m is 0, n is 1, R⁵ isalkoxyalkyl, and R⁷ is hydrogen.
 26. The composition of claim 1 whereinR¹ is [mercaptoalkyl or] mercaptoalkoxycarbonylalkyl.
 27. Thecomposition of claim 1 wherein X is phenoxy, m is 0, and n is
 1. 28. Thecomposition of claim 27 wherein R¹ is hydroxyalkyl.
 29. The compositionof claim 1 wherein X is benzyl, R⁷ is hydroxyl, and m and n are
 0. 30.The composition of claim 29 wherein R¹ is hydroxyalkyl.
 31. Thecomposition of claim 1 wherein the polymeric composition comprises ahalogen-containing polymer.
 32. The composition of claim 31characterized further by the presence of a metallic-based heatstabilizer.
 33. The composition of claim 32 wherein at least one of themetallic-based heat stabilizers is selected from the group consisting ofantimony-, barium-, magnesium-, and calcium-, tin-, and zinc-basedstabilizers.
 34. The composition of claim 32 wherein the metallic-basedheat stabilizer is an organometal compound.
 35. The composition of claim34 wherein the metallic-based heat stabilizer is an organotin compound.36. The composition of claim 35 wherein the organotin compound is anorganotin mercaptide.
 37. The composition of claim 36 wherein themercaptide moiety is an alkyl thioglycolate.
 38. The composition ofclaim 36 wherein the mercaptide moiety is a mercaptoalkyl carboxylate.39. The composition of claim 34 wherein the metallic-based heatstabilizer is an organometal mercaptoester sulfide.
 40. The compositionof claim 39 wherein the mercaptide moiety of the organometalmercaptoester sulfide is an alkyl thioglycolate.
 41. The composition ofclaim 39 wherein the mercaptide moiety of the organometal mercaptoestersulfide is a mercaptoalkyl carboxylate.
 42. The composition of claim 39wherein the organometal is an organotin.
 43. The composition of claim 31wherein the halogen-containing polymer is a vinyl chloride polymer. 44.The composition of claim 31 wherein a is 1, m and n are 0, y and z are1, X is hydroxyphenyl, R⁴ is hydrogen, R⁵ is hydrogen or alkyl, R⁷ isalkoxy, and R¹ is hydroxyalkyl.
 45. The composition of claim 31 whereina is 1, m is 1, n is 0, y and z are 1, X is hydroxyphenyl, R⁴ and R⁵ arehydrogen, R⁶ is alkenyl, R⁷ is alkoxy, and R¹ is hydroxyalkyl.
 46. Thepolymeric composition of claim 1 wherein said blocked mercaptan has thestructure:

wherein a is 0 or 1, m and n are 0 or 1; y=1 to 4, when y=1, z is 1 to 4when y is more than 1 z is 1; R1 is a hydroxyalkyl, dihydroxyalkyl,hydroxy(polyalkoxy)alkyl, alkoxyalkyl, hydroxyalkoxyalkyl,alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl), alkoxy(polyalkoxy)alkyl,carboxyalkyl, acyloxyalkyl, acyloxy (hydroxyalkyl), acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxy)carbonylalkyl, alkoxy(polyalkoxy) carbonylalkyl,mercaptoalkyl, mercaptoalkylenyl, mercaptoalkoxycarbonylalkyl,mercaptoalkoxycarbonylalkylenyl, alkoxycarbonyl(amido)alkyl,alkylcarbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, R⁶, and R⁷ are independently hydrogen, ahydroxyl, mercapto, alkyl, alkylenyl, aryl, haloaryl, alkaryl, aralkyl,hydroxyalkyl, mercaptoalkyl, mercaptoalkylenyl, hydroxyaryl, alkoxyaryl,alkoxyhydroxyaryl, arylcarbonyl, or mercaptoaryl radical having from 1to 22 carbon atoms; when a=1, X is arylcycloalkyl or a heteroatom, andwhen a=0, X is aryl, haloaryl, alkaryl, alkoxyaryl, arylcycloalkyl, or aheteroatom, with the option that when a is 1 and m is 0, one of the R³and R⁵ radicals joins with R⁷ and X to form a heterocyclic moiety with Xas a heteroatom selected from the group consisting of oxygen and sulfur,and with the further option that when a is 1 and m is 1, R⁶ and R⁷ forma heterocyclic moiety in conjunction with X as a nitrogen atom.
 47. Ablocked mercaptan having the structure:

wherein a is 0 or 1, m and n are 0 or 1; y=1 to 4, when y=1, z is 1 to 4when y is more than 1 z is 1; R1 is a hydroxyalkyl, dihydroxyalkyl,hydroxy(polyalkoxy)alkyl, alkoxyalkyl, hydroxyalkoxyalkyl,alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl), alkoxy(polyalkoxy)alkyl,carboxyalkyl, acyloxyalkyl, acyloxy (hydroxyalkyl), acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxy)carbonylalkyl alkoxy (polyalkoxy) carbonylalkyl,mercaptoalkyl, mercaptoalkylenyl, mercaptoalkoxycarbonylalkyl,mercaptoalkoxycarbonylalkylenyl, alkoxycarbonyl(amido)alkyl,alkylcarbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, R⁶, and R⁷ are independently hydrogen, ahydroxyl, mercapto, alkyl, alkylenyl, aryl, haloaryl, alkaryl, aralkyl,hydroxyalkyl, mercaptoalkyl, hydroxyaryl, alkoxyaryl, alkoxyhydroxyaryl,arylcarbonyl, or mercaptoaryl radical having from 1 to 22 carbon atoms;when a=1, X is arylcycloalkyl or a heteroatom, and when a=0, X is aryl,haloaryl, alkaryl, hydroxyaryl, dihydroxyaryl, alkoxyaryl,arylcycloalkyl, or a heteroatom; with the option that when a is 1 and mis 0, R⁵ joins with R⁷ and X to form a heterocyclic moiety with X as aheteroatom selected from the group consisting of oxygen and sulfur, andwith the further option that when a is 1 and m is 1, R⁶ and R⁷ form aheterocyclic moiety in conjunction with X as a nitrogen atom.
 48. Acomposition for stabilizing PVC consisting essentially of ametallic-based stabilizer for PVC and a latent mercaptan having theformula

wherein a is 0 or 1, m and n are 0 or 1; y=1 to 4, when y=1, z is 1 to 4when y is more than 1 z is 1; R¹ is a hydroxyalkyl, dihydroxyalkyl,hydroxy(polyalkoxy) alkyl, alkoxyalkyl, hydroxyalkoxyalkyl,alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl), alkoxy(polyalkoxy)alkyl,carboxyalkyl, acyloxyalkyl, acyloxy(hydroxyalkyl), acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxy)carbonylalkyl, alkoxy(polyalkoxy)carbonylalkyl,mercaptoalkyl, mercaptoalkylenyl, mercaptoalkoxycarbonylalkyl,mercaptoalkoxycarbonylalkylenyl, alkoxycarbonyl(amido)alkyl,alkylcarbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, R⁶, and R⁷ are independently hydrogen, ahydroxyl, mercapto, alkyl, alkylenyl, aryl, haloaryl, alkaryl, aralkyl,hydroxyalkyl, mercaptoalkyl, hydroxyaryl, alkoxyaryl, alkoxyhydroxyaryl,arylcarbonyl, or mercaptoaryl radical having from 1 to 22 carbon atoms;X is aryl, haloaryl, alkaryl, hydroxyaryl, dihydroxyaryl, aralkaryl,alkoxyaryl, arylcycloalkyl, or a heteroatom, with the option that when ais 1 and m is 0, one of the R³ and R⁵ groups joins with R⁷ and X to forma heterocyclic moiety with X as a heteroatom selected from the groupconsisting of oxygen, and sulfur, and with the further option that whenm is 1, R⁶ and R⁷ may form a heterocyclic moiety in conjunction with Xas a nitrogen atom; with the proviso that when X is aralkaryl, R⁶ and R⁷are hydroxyl, a is 1 and m is 1, then z is 1 or 2; and with the furtherproviso that when R⁶≠hydroxyl or mercapto, z is
 1. 49. The compositionof claim 48 further characterized by the presence of a biocide.
 50. Thecomposition of claim 49 wherein the biocide is 10,10′-oxybisphenoxarsine.
 51. The composition of claim 1 characterizedfurther by the presence of an antioxidant which is a blocked mercaptanhaving the structure of Formula 1 wherein a is 1, m and n are 0, y and zare 1, X is phenyl, R⁴ and R⁵ are hydrogen, R⁷ is hydroxy, and R¹ ishydroxyethyl.
 52. The composition of claim 1 characterized further bythe presence of an antioxidant which is a blocked mercaptan having thestructure of Formula 1 wherein a is 1, m and n are 0, y is 1, z is 2, Xis phenyl, R⁴ is hydrogen, R⁵ is ethyl, R⁷ is hydroxy, and R¹ ishydroxyethyl.
 53. A composition capable of stabilizing ahalogen-containing polymer against deterioration caused by heat, saidcomposition comprising the blocked mercaptan of claim 45 as the soleheat stabilizer,
 54. The composition of claim 53 wherein a is 1, m is 0,n is 0, y is 1, z is 1, X is 0, R⁵ and R⁷ are joined with X to form aheterocyclic moiety, R⁴ is hydrogen, and R¹ is hydroxyalkyl.
 55. Thecomposition of claim 53 wherein a is 1, m and n are 0, y and z are 1, Xis phenyl, R⁷ is o-hydroxy, R⁴ is hydrogen, R⁵ is alkyl, and R¹ ishydroxyalkyl.
 56. The composition of claim 31 characterized further bythe presence of from 0.01 to 10% of a phenolic antioxidant by weight ofthe halogen-containing resin.
 57. The composition of claim 56 whereinthe amount of antioxidant is from 0.1-5% of the.halogen-containingresin.
 58. The composition of claim 56 wherein R¹ is hydroxyethyl.
 59. Apolymeric composition comprising a photostabilizer to retarddiscoloration caused by ultra-violet radiation, said photostabilizerhaving the general formula:

wherein a is 1, m and n are 0; y and z=1, X is o, p,-dihydroxyphenyl, R1is hydroxyalkyl, R⁴, is hydrogen, R⁵ is alkyl, and R⁷ is am-phenylcarbonyl radical.
 60. A method for the preparation of a heatstabilizer for halogen-containing polymers, said method comprisingcondensing a para-substituted phenol with formaldehyde in the presenceof an alkali metal hydroxide in aqueous solution at a temperature of upto about 60° C., wherein the ratio of the phenol to formaldehyde is from1:1 to about 1:1.05 on an equivalent weight basis, and the molar ratioof the phenol to alkali metal hydroxide is about 1:1, quenching thecondensation by cooling the reaction mixture below 20° C., neutralizingthe mixture, isolating the resultant condensate, and further condensingthe resultant condensate without further purification with amercaptan-containing compound selected from the group consisting ofalkyl mercaptans, mercapto esters, mercapto alcohols, and mercapto acidsat from about 400 to about 120° C. in the presence of an acid catalyst.61. The method of claim 60 wherein the maximum temperature during thephenol/formaldehyde condensation is about 50° C.
 62. The method of claim61 wherein the temperature is from about 35° to about 50° C.
 63. Themethod of claim 60 wherein the total concentration of phenolic andformaldehyde reactants is from about 25 to about 50% by weight.
 64. Acompound having the formula AB_(b) wherein wherein A is Sn, Ba, Ca, Al,Mg, monoalkyltin, dialkyltin, or trialkyl tin, B has the formula:

m and n are 0 or 1, X is aryl, alkaryl, or haloaryl, R1 is an alkyl,alkylenyl, cycloalkyl, cycloalkylenyl, aryl, alkaryl, aralkyl,aralkylenyl, hydroxyalkyl, dihydroxyalkyl, hydroxy(polyalkoxy)alkyl,alkoxyalkyl, hydroxyalkoxyalkyl, alkoxy(hydroxyalkyl),alkoxy(acyloxyalkyl), alkoxy(polyalkoxy)alkyl, carboxyalkyl,acyloxyalkyl, acyloxy(hydroxyalkyl) , acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxy)carbonylalkyl, alkoxy(polyalkoxy)carbonylalkyl,mercaptoalkyl, mercaptoalkylenyl, mercaptoalkoxycarbonylalkyl,mercaptoalkoxycarbonylalkylenyl, alkoxycarbonyl(amido)alkyl,alkylcarbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, and R⁶ are, independently, hydrogen, ahydroxyl, mercapto, acyl, alkyl, alkylenyl, aryl, haloaryl, alkaryl,aralkyl, hydroxyalkyl, mercaptoalkyl, hydroxyaryl, alkoxyaryl,alkoxyhydroxyaryl, or mercaptoaryl radicals having from 1 to 22 carbonatoms; R⁸ is o⁻ or S⁻, z is 1 or 2, and b is from 1 to
 4. 65. Thecompound of claim 64 wherein A is dibutyltin, m and n are 0, z is 1, Xis phenyl, R⁴ and R⁵ are hydrogen, R⁸ is o⁻, R¹ is hydroxyethyl, and bis
 2. 66. A polymeric composition comprising the compound of claim 65 asa heat stabilizer.
 67. The composition of claim 66 wherein the polymeris a halogen-containing polymer.
 68. A compound having the formulaPQ_(p)B_(3−p) wherein P is phosphorus, Q is an alkoxy, aryloxy,aralkoxy, alkaryloxy, or haloaryloxy radical, p is 1 or 2 and B is

wherein n is 0 or 1; z is 1 or 2; X is aryl, haloaryl, orarylcycloalkyl, R1 is an alkyl, alkylenyl, cycloalkyl, cycloalkylenyl,aryl, alkaryl, aralkyl, aralkylenyl, hydroxyalkyl, dihydroxyalkyl,hydroxy(polyalkoxy) alkyl, alkoxyalkyl, hydroxyalkoxyalkyl,alkoxy(hydroxyalkyl), alkoxy(acyloxyalkyl), alkoxy(polyalkoxy)alkyl,carboxyalkyl, acyloxyalkyl, acyloxy(hydroxyalkyl), acyloxyalkoxyalkyl,acyloxy(polyalkoxy)alkyl, benzoyloxy(polyalkoxy)alkyl,alkylenebis-(acyloxyalkyl), alkoxycarbonylalkyl,alkoxycarbonylalkylenyl, hydroxyalkoxycarbonylalkyl,hydroxy(polyalkoxycarbonylalkyl, alkoxy(polyalkoxy)carbonylalkyl,mercaptoalkyl, mercaptoalkylenyl, mercaptoalkoxycarbonylalkyl,mercaptoalkoxycarbonylalkylenyl, alkoxycarbonyl(amido)alkyl,alkylcarbonyloxy(polyalkoxy)carbonylalkyl,tetrahydopyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl,hydroxyaryl, mercaptoaryl or carboxyaryl radical having from 1 to 22carbon atoms; R², R³, R⁴, R⁵, and R6 are independently hydrogen, ahydroxyl, mercapto, acyl, alkyl, alkylenyl, aryl, haloaryl, alkaryl,aralkyl, hydroxyalkyl, mercaptoalkyl, hydroxyaryl, alkoxyaryl,alkoxyhydroxyaryl, mercaptoaryl groups having from 1 to 22 carbon atoms;and R⁸ is 0⁻.
 69. A polymeric composition comprising ahalogen-containing polymer, a primary mercaptan-containing heatstabilizer, and odor-masking latent mercaptan having the structure

wherein a is 1, m and n are 0; y is 1; z is 1; R¹ is hydroxyalkyl, R⁴and R⁵ are independently hydrogen or alkyl, R⁷ is selected from thegroup consisting of hydroxy, alkoxy, and alkenyl; and X is hydroxyarylor alkoxyaryl.
 70. The composition of claim 69 wherein the concentrationof the latent mercaptan is from about 0.01 to about 0.1 part per hundredparts of the halogen-containing polymer.
 71. A chelating agent havingthe structure of Formula 1 wherein a is 2, m is 1, n is 0, y is 2, X isphenyl, R¹ is ethyloxyethyl, R⁶ is hydroxyl, and R⁷ is methyl.
 72. Achelating agent having the structure of Formula 1 wherein a is 1, m andn are 0, y is 1, X is oxygen, R¹ and R⁷ join with X to form aheterocyclic moiety, and R¹ is a hydroxy(polyethoxy)carbonylalkylradical.